Beach Ecology

From Beachapedia
Jump to: navigation, search

By Clara Cartwright

Contents

The State of Beach Ecology

Beaches are alive. They are home to birds, grasses, crabs, clams, fish, tiny invertebrates, and more. Unfortunately, these habitats are experiencing an unprecedented level of human impact, encroached on the landward side by coastal development and on the ocean side by sea level rise and coastal erosion. Beach ecosystems are affected by many different types of human pressures, from recreation to pollution to coastal armoring. As a coastal ecosystem, the beach is underrepresented in science and largely unrecognized in management practices. The Coastal Zone Management Act calls for “The protection of natural resources, including…beaches, dunes, barrier islands…and fish and wildlife, and their habitat, within the coastal zone” (1972). Our findings in the State of the Beach report revealed that despite this federal mandate, sandy beaches all around the nation are receiving little, if any, ecological protection. Therefore, coastal managers must make three key changes with respect to sandy beach ecology: there must be widespread recognition of the beach as a natural ecosystem, managers need to better incorporate existing science into beach management, and research in beach ecology must advance.

Beach Wrack/Beach Ecology sign in Sarasota County, Florida



The Surfrider Foundation has been evaluating state coastal zone management for beach ecology since 2004. We recently refined our rating system to focus specifically on beach ecology, as opposed to a broader view that included other coastal ecosystems. While no state provided enough information to determine the status of beach ecological health, we were able to give states an “information” score based on their policies and the amount of information they have related to beach ecology. Unfortunately, we found that state coastal zone managers have made little progress in protecting beach ecology since the scores were created seven years ago. Nine out of 32 states received a score of 1, which means that they have no information or policies related to beach ecology. The majority of states (69%) had a grade of 3 or worse. This large amount of low scores shows that states generally still do not recognize beach ecology as a resource to be protected and are not incorporating scientific knowledge of beach ecology into their coastal management practices.

Beach Ecology1.png
Beach Ecology2.png



Most fundamentally, state coastal zone managers need to recognize that beaches have value as ecosystems. Sandy beaches provide many ecosystem services, including: sediment storage and transport; wave dissipation and associated buffering against extreme weather events; dynamic response to sea level rise; breakdown of organic materials and pollutants; water filtration; nutrient mineralization and recycling; storage of water in dune aquifers and groundwater discharge through beaches; maintenance of biodiversity and genetic resources; providing a nursery area for juvenile fishes; nesting sites or rookeries for turtles, shorebirds, and pinnipeds; prey for birds and other terrestrial wildlife; scenic vistas and recreational opportunities; and functional links between terrestrial and marine environments (Defeo et al., 2009). Only a handful of states, such as Washington, Oregon, Massachusetts, and Delaware, already recognize beaches as natural ecosystems full of life. These states use science to inform management decisions and provide models that other states can follow. Unfortunately, most states manage beaches solely for their physical or recreational values. For example, the coastal management plans for Alabama, Hawaii, and Pennsylvania do not seem to recognize beaches as having their own intrinsic ecology – an ecology that is linked to the adjacent terrestrial and marine ecologies. While physical and recreational aspects of sandy beaches are important, management decisions will never be optimal for society without also considering the ecological value of sandy beaches.

While states differ in how strongly they embrace beaches as ecosystems, all managers must do a better job of incorporating science into beach management. The ecological knowledge currently utilized in beach management is generally limited to direct human disturbance of species. For example, most beach managers in California recognize that beach grooming can dig up and destroy grunion eggs, so they use modified grooming practices during the grunion spawning season; this management has resulted in greater protection for the grunion. Another example concerns the direct effects of humans on sea turtles: beach driving can destroy turtle eggs and kill hatchlings, and lights will scare away nesting females and disorient hatchlings. South Carolina responded to these findings by prohibiting beach driving during the turtle nesting season and requiring its coastal communities to adopt turtle-friendly lighting ordinances. Beaches in Florida and North Carolina also provide nesting habitat for sea turtles; however, these states do not have the same protections in place. More states need to start managing for the protection of beach ecology by implementing this basic knowledge of direct human impact.

More recent research describes the effects of beach management activities on ecological structures and processes, and managers need to incorporate this newer knowledge into their practices. Vehicle use on the beach was found to have a significant negative effect on invertebrate abundance and diversity (Schlacher, Richardson, & McLean, 2008). Seawalls result in narrower intertidal zones, altered wrack assemblages, and reduced numbers of invertebrates and shorebirds (Dugan & Hubbard, 2006). Beach grooming also results in decreased species abundance and biomass (Dugan, Hubbard, McCrary, & Pierson, 2003; Hubbard, Dugan, Schooler & Viola, 2013). Even beach nourishment (adding sand to the beach), often considered an ecologically preferred option for erosion defense, has detrimental ecological effects (Speybroeck et al., 2006), (Manning, Peterson, & Fegley, 2013), (Viola, Hubbard, Dugan, and Schooler, 2013). This research reveals how efforts to “maintain” the beach actually significantly impact beach ecology.

Delaware and Florida have completed studies to better understand the ecological effects of their beach management practices. In Delaware, coastal zone managers researched the effect of beach nourishment on spawning populations of the horseshoe crab. They found that if carried out with a specific method and with the right kind of sand, beach nourishment can actually improve spawning habitat for this species (Smith et al., 2002). Florida’s Department of Environmental Protection (DEP) carried out a beach nourishment project on Hutchinson Island, and used this project to study the effects on nesting loggerhead turtles. Monitoring before, during, and after the project produced information that future beach nourishment projects can use to decrease the indirect impacts on this threatened species (Ecological Associates, Inc., 1999). These studies show how scientific monitoring of current practices can inform and improve future practices, and they provide examples to state agencies as they develop a more integrated approach to caring for their beaches.

In California, the Beach Ecology Coalition has developed Best Management Protocols for grunion nesting areas on beaches, beach driving, fire ring safety and plant management. Also in California, the Sea Grant Extension Program has developed an Explore Sandy Beach Ecosystems of Southern California website which is a great resource that allows you to:

"...learn about plants that build dunes, fish that run onto land, and crabs that move incredible distances migrating with the tide. Discover the dynamic process of sand movement and the impacts of beach grooming, coastal armoring, and nourishment on beaches and beach ecosystems. Understand challenges and success stories related to climate change impacts on beaches. Lastly, consider what you can do by reading the best practices information for beach goers, managers and city/county planners."

Many states, however, do not use available data and scientific studies to inform their beach management decisions. Beach nourishment projects on the east coast continue to use ecologically incompatible sediment that contains too much mud and shells, and in one case from New Jersey, unexploded bombs from World War I (Capuzzo, 2007). In Florida, despite its research to protect nesting sea turtles, the DEP has recently changed its rules to allow nourishment projects to use contaminated sand and forgo any evaluation of ecological consequences (Littlejohn, 2011). As long as practices like these continue in ignorance of existing knowledge, beach ecology will be in dire straits.

Some states do a terrible job of protecting beach ecology, and some do a better job, but one area where all states need to improve is on measuring the ecological health of their beaches. Right now, no state uses ecological indicators to determine the status of beach health. Washington, however, has created a long-term goal to develop ecological indicators and use them as part of a comprehensive marine spatial plan (Hennessey, Nichols, & The State Ocean Caucus, 2011). A system to measure ecological health is vital to making sound management decisions and determining whether those decisions actually result in the desired level of ecological health. Without an established system of indicators to measure beach health, managers cannot know how their decisions affect beach ecology.

Even if all states recognized the value of beach ecology and used the most recent science to inform management, their efforts to successfully protect these ecosystems would still be hindered by a lack of scientific knowledge. Advances in research are needed to understand the more complex effects of management practices on sandy beach ecosystems. Topics yet to be explored include determining the value of ecosystem services, the effects of habitat loss and fragmentation on ecological health, the effects of human pressure on ecosystem processes at larger spatial scales and over longer time spans, and the effects of climate change on beach ecology (Dugan et al., 2010; Schlacher et al., 2007). Science is still at an early stage in understanding sandy beach ecology and its vulnerability to human pressures. Our knowledge of these ecosystems must improve in order to inform ecologically sound management decisions.

The ecological health of beaches depends on better management practices and growth of scientific knowledge. Only when coastal zone managers make a fundamental shift in the way they think about the beach and recognize its ecological value will they be able to make informed decisions about beach management practices. Scientists need to gain a deeper understanding of beach ecosystems and their responses to a wide range of human pressures. Managers and scientists should work together to create sound management and monitoring practices and determine how healthy their beaches truly are. It is time for us to know the state of the beach.

Three case studies take an in-depth look into the current state of management for beach ecology around the country. First, we look at beach grooming in California and the ecological protection that has been achieved through a collaborative effort. Next, we examine beach nourishment in Florida, a practice that remains a struggle between economic interests and environmental integrity. Finally, we glimpse into the future, when states will take a truly integrated, ecosystem-based approach to coastal management, fully incorporating sandy beach ecology into the decision-making process.

Sources

  1. Capuzzo J.P. (2007, May 15). After ordnance scare, beachgoers told to dig with care. New York Times. Retrieved from http://www.nytimes.com/2007/05/15/nyregion/15sand.html
  2. Coastal Zone Management Act of 1972 §303(2)(A), 16 U.S.C. §1452 (1972).
  3. Defeo, O., McLachlan, A., Schoeman, D. S., Schlacher, T. A., Dugan, J., Jones, A., Lastra, M., & Scapini, F. (2009). Threats to sandy beach ecosystems: a review. Estuarine, Coastal and Shelf Science, 81, 1-12.
  4. Dugan J. E., Hubbard D. M., McCrary M. D., & Pierson M. O. (2003). The response of macrofauna communities and shorebirds to macrophyte wrack subsidies on exposed sandy beaches of southern california. Estuarine, Coastal and Shelf Science, 58S, 25-40.
  5. Dugan J. E., Hubbard D. M. (2006). Ecological responses to coastal armoring on exposed sandy beaches. Shore & Beach, 74 (1), 10-16.
  6. Dugan J. E., Defeo O., Jaramillo E., Jones A. R., Lastra M., Nel R., Peterson C. H., Scapini F., Schlacher T., Schoeman D. S. (2010). Give beach ecosystems their day in the sun. Science, 329, 1146. Retrieved from www.sciencemag.org
  7. Ecological Associates, Inc. (1999). Martin county beach nourishment project: sea turtle monitoring and studies 1997 annual report and final assessment. Jensen Beach, FL: Ernest R. G. & Martin R. E.
  8. Hennessey, J., Nichols, B., & The State Ocean Caucus, Eds. (2011). Marine spatial planning in Washington: final report and recommendations of the state ocean caucus to the Washington state legislature (Washington Department of Ecology publication No. 10-06-027). Olympia, WA.
  9. Hubbard D. M., Dugan J. E., Schooler N. K. & Viola S. M. (2013). Local extirpations and regional declines of endemic upper beach invertebrates in southern California, Estuarine, Coastal and Shelf Science, DOI: 10.1016/j.ecss.2013.06.017
  10. Littlejohn, J. (2011). Memorandum: Beach program improvements (Florida Department of Environmental Protection).
  11. Manning, Lisa M.; Peterson, Charles H.; Fegley, Stephen R. "Degradation of Surf-Fish Foraging Habitat Driven by Persistent Sedimentological Modifications Caused by Beach Nourishment." Bulletin of Marine Science, Volume 89, Number 1, January 2013, pp. 83-106(24)
  12. Schlacher, T. A., Dugan, J., Schoeman, D. S., Lastra, M., Jones, A., Scapini, F., McLachlan, A., & Defeo, O. (2007). Sandy beaches at the brink. Diversity and Distributions, 13, 556-560.
  13. Schlacher, T. A., Richardson, D., & McLean, I. (2008). Impacts of off-road vehicles (ORVs) on macrobenthic assemblages on sandy beaches. Environmental Management, 41, 878-892.
  14. Smith, D., Jackson, N., Love, S., Nordstrom, K., Weber, R., & Carter, D. (2002). Beach nourishment on Delaware bay beaches to restore habitat for horseshoe crab spawning and shorebird foraging (Prepared for Maria Trabka, The Nature Conservancy, Delaware Bayshore Office). Wilmington, DE.
  15. Speybroeck, J., Bonte, D., Courtens, W., Gheskiere, T., Grootaert, P., Maelfait, J., Mathys, M., Provoost, S., Sabbe, K., Stienen, E. W., Van Lancker, V., Vincx, M., & Degraer, S. (2006). Beach nourishment: an ecologically sound defence alternative? a review. Aquatic Conserv: Mar. Freshw. Ecosyst., 16, 419-435.
  16. Viola, S., Hubbard, D., Dugan, J., Schooler, N. (2013). Burrowing inhibition by fine textured beach fill: Implications for recovery of beach ecosystems. Estuarine, Coastal and Shelf Science.



Case Studies

Beach Grooming in California

California beaches provide enjoyment for both local residents and tourists, and they support a significant part of the economy for coastal communities. Beach grooming is a widely used practice along the heavily used beaches of Southern California to keep the sand clear of both natural debris and trash in order to keep the beach appealing for recreation. However, this practice also significantly disturbs the sandy beach ecosystem. Over the last few years local beach managers have worked together with scientists, government agencies, environmental groups, and concerned citizens to develop grooming practices that strike a better balance between the economic and ecological assets of the beach. The success of these modified beach maintenance practices demonstrates the importance of basing environmental management in sound science and supporting collaboration among many diverse stakeholders.

The high tide line is an ecologically vibrant zone on the beach. Kelp and sea grasses wash up to this zone, forming what is called the wrack line. As the wrack breaks down, it provides nutrients that form the base of the food chain on the beach, supporting everything from tiny invertebrates to shorebirds. Many nutrients from the wrack also filter through the sand and make their way back out to the water, supporting the nearshore marine ecosystem (Dugan, Hubbard, Page, & Schimel, 2011). Both wrack at the high tide line and plants growing on the upper beach help to reduce the impact of the wind, protecting the sand from erosion (Dugan & Hubbard, 2010). These processes are essential to maintaining a healthy beach ecosystem.

The high tide line is also the site of a spectacular spawning ritual for a small, silver fish. The California grunion, Leuresthes tenius, is endemic to the California coast, and the vast majority of spawning events occur between Santa Barbara and San Diego. Between March and July, on nights of the spring tide (the highest tides that occur just after the full and new moons), thousands of grunion swim out of the ocean and spawn on the beach, burying their fertilized eggs in the sand. The eggs mature in dry sand over the next two weeks and then hatch in response to waves from higher tides, which carry the larvae out to the ocean.

It comes as no surprise, then, that beach grooming has severe consequences for the beach ecosystem. Beach rakes dig up and destroy grunion eggs, limiting reproductive success for the species (Martin, Speer-Blank, Pommerening, Flannery, & Carpenter, 2006). Grooming also removes wrack, depriving many organisms of their natural food source. Groomed beaches have lower numbers and fewer species of invertebrates, an essential food for shorebirds (Dugan, 2003). Wrack removal also eliminates the ecosystem’s natural method for minimizing sand erosion (Dugan & Hubbard, 2010). For many years, most beach managers in Southern California groomed the entire beach, including the sensitive high tide zone, on a regular basis without acknowledging or understanding the harm it was causing to the ecosystem.

The push for ecological protection started in 2001 when a group of concerned citizens convinced the City of San Diego that their beach grooming practices were harmful to grunion spawning success. The city responded by agreeing to the creation of a panel to explore the effects of grooming on grunion eggs (Perry, 2001). Melissa Studer, a marine conservationist, created and organized the panel at the request of the city. As a result of panel discussions, Studer started working with Dr. Karen Martin, a grunion expert and panel member, to develop a volunteer-based program to monitor grunion runs on San Diego beaches. In 2002, Grunion Greeters was born, and 200 trained volunteer grunion observers collected data on spawning events. In addition to the volunteer monitoring, Dr. Martin conducted a scientific experiment to see if grunion eggs in groomed sand were less likely to hatch than eggs in un-groomed sand. The study showed that beach grooming destroyed grunion eggs, significantly affecting grunion reproduction (Martin et al., 2006). The city took this finding into consideration and created a Grunion Grooming protocol that prohibits grooming below the high tide line during the grunion spawning season.

Over the next several years, Melissa Studer and Karen Martin expanded their army of citizen scientists. As it grew, Grunion Greeters also developed partnerships with numerous environmental groups, aquariums, and government agencies along the coast. In 2010, Grunion Greeters had 560 volunteers observing grunion runs from San Diego to Santa Barbara (M. Studer, personal communication, August 6, 2011). These volunteers have helped not only by reporting observations, but also by voicing their concern for the grunion to local governments, who in several cases responded by making their beach grooming practices more grunion friendly (Martin et al., 2007). Involving the public in grunion monitoring has raised the call for grunion protection from a few scientists to hundreds of ordinary citizens and has increased the effectiveness of communicating with local beach managers.

As public awareness about grunions was growing stronger, an equally important shift was taking place among coastal managers. Dennis Simmons, beach manager for the City of San Diego, strongly supported the changes in beach grooming and decided to share his knowledge with other beach managers. In 2004, Simmons and Martin teamed up to form the Beach Ecology Coalition, a working group comprised of local beach managers, government agencies, nonprofit organizations, and scientists, to share information about the grunion and to advocate ecologically friendly beach management practices. Since 2004, the Beach Ecology Coalition has grown from 15 members to 300 (K. Martin, personal communication, August 9, 2011). Because beach managers were given a way to come together and discuss beach ecology, this notion of grunion friendly grooming was able to grow and become accepted at a rapid pace.

In addition to Grunion Greeters and the Beach Ecology Coalition, the California Coastal Commission has also contributed to the widespread changes in beach grooming practices. The Coastal Commission is the state regulatory agency for coastal land use issues, and while it does not directly regulate beach grooming, it works closely with beach managers to develop more ecologically sensitive beach management practices. Jonna Engel and Aaron McLendon, staff members on the Coastal Commission, also serve on the advisory board for the Beach Ecology Coalition and are very dedicated to the group’s success (J. Engel, personal communication, August 23, 2011). The Coastal Commission also urges communities to implement modified grooming practices when they update their Local Coastal Plans (California Coastal Commission, 2007). So far, the cities of Santa Cruz and Santa Barbara have incorporated these practices into their plans (Craig, 2006; Hetrick, 2006). The state government’s support continues to be an important factor in motivating local governments to improve their beach management practices.

All of these programs—Grunion Greeters, the Beach Ecology Coalition, and government agencies such as the Coastal Commission—together generated enough momentum to create sweeping changes in beach grooming practices across the state. Today, over 90% of previously groomed beaches in California have altered their practices to follow grunion friendly grooming protocols (K. Martin, personal communication, August 9, 2011). The strategy includes grooming the middle stretch of the beach and avoids both the intertidal zone and the upper beach vegetation. This compromise allows beachgoers to enjoy a clean area for their towel while protecting the ecologically vibrant zone near the water. Although this strategy sacrifices ecological health on the middle beach, this zone is perhaps the least ecologically diverse on many beaches; sacrificing this zone results in the least damage to the beach as a natural system.

Protecting grunion as a charismatic species has brought California far in its beach management practices, and can be used as a starting point to including all important components of the beach ecosystem. This fish has given both the public and government agencies an aspect of beach ecology they can relate to. Modifying grooming practices for this species also helped to protect many other species and ecological processes in the intertidal zone. While using an iconic species to protect the larger ecosystem has resulted in much progress, the next step for beach groomers is to move beyond grunions to consider the beach ecosystem as a whole. Sandy beaches have many ecological functions that provide value to our society but currently are less recognized by coastal managers. The ideal beach maintenance protocol would create a standard set of practices that take these natural services into consideration and result in a beach that maximizes all of its benefits, both recreational and ecological.

Beach grooming in California has undergone a large shift toward beach ecology protection over the last 10 years. Grunion Greeters and the Beach Ecology Coalition have played major roles in the process, generating widespread awareness about the grunion and increasing collaboration among many different stakeholders. Coastal managers statewide have shown that it is possible to maintain the beach for both a healthy economy and a healthy ecosystem.

Key Concepts

  • Using scientific knowledge to inform beach management practices will help to create a balanced strategy that supports beach ecology.
  • Collaboration among different government agencies and stakeholder groups is key to successful management of beach ecology.
  • Educating the public and raising awareness about issues in beach ecology will motivate action to protect the beach.
  • Protection for a charismatic species makes beach ecology relatable to the public, but limits management to only one aspect of beach ecology.


Sources

1. California Coastal Commission. (2007). LCP update guide: sensitive habitats and natural resources. San Francisco, CA.

2. Craig, S. (2006). Coastal development permit amendment 3-95-043-A2. (California Coastal Commission permit amendment no. 3-95-043-A2). Santa Cruz, CA.

3. Dugan, J. (2003). Ecological impacts of beach grooming on exposed sandy beaches. Research Summaries, California Sea Grant College Program, UC San Diego.

4. Dugan, J., Hubbard, D. (2010). Loss of coastal strand habitat in southern California: the role of beach grooming. Estuaries and Coasts, 33, 67-77.

5. Dugan, J., Hubbard, D., Page, H., Schimel, J. (2011). Marine macrophyte wrack inputs and dissolved nutrients in beach sands. Estuaries and Coasts, 34(4), 839-850.

6. Hetrick, M. (2006). Santa Barbara sediment management program (California Coastal Commission application no. 4-05-155). Ventura, CA.

7. Martin, K., Speer-Blank, T., Pommerening, R., Flannery, J., & Carpenter, K. (2006). Does beach grooming harm grunion eggs? Shore & Beach, 74(1), 17-22.

8. Martin, K., Staines, A., Studer, M., Stivers, C., Moravek, C., Johnson, P., & Flannery, J. (2007). Grunion greeters in California: beach spawning fish, coastal stewardship, beach management and ecotourism. Proceedings of the 5th International Coastal & Marine Tourism Congress: balancing marine tourism, development and sustainability. Aukland, New Zealand: The School of Hospitality and Tourism Research Institute, AUT University.

9. Perry, T. (2001, July 22). San Diego hatches plan to protect grunion spawning sites at beaches. Los Angeles Times.

Beach Nourishment and Beach Ecology

Beach nourishment, also known as beach restoration or beach fill, is a coastal management strategy where sand is retrieved from a marine or land “borrow site” and deposited onto the beach. Coastal managers use beach nourishment to combat coastal erosion, protect coastal infrastructure, and to widen the beach in order to increase revenue from recreation. Today, beach nourishment is considered the environmentally preferred erosion response compared to using hard structures such as seawalls. However, this “preferred” method can be highly stressful to both nearshore and sandy beach habitats. One recent nourishment project in Palm Beach, Florida shows just how ecologically devastating this practice can be for the sandy beach, especially when poor management decisions are involved. Since these projects will continue to be the primary erosion response approach used for at least the next several decades, we need to start doing them in a way that reduces the impacts to beach ecology.

Over the last few decades, Florida has been fighting against increasing levels of coastal erosion. Florida historically had few inlets, but as the state developed, many more were constructed. These additional inlets disrupted the natural transport of sand along the coast, depriving many beaches of their sand supply (Wanless, 2009). In addition, sea level rise and stronger storms exacerbated by climate change have eroded away more sand, and will continue to do so in the foreseeable future. Beaches naturally respond to erosion by migrating landward. However, much of Florida’s coastline has been developed right up to the beach; as the beaches erode, they have nowhere to migrate and instead disappear. In order to combat this loss of sand and protect coastal structures, Florida has turned increasingly to beach nourishment.

Unfortunately, beach nourishment has turned out to be a far from perfect solution for the state. Florida’s native beach sand is a quartz-carbonate mixture and is added very slowly to the littoral system from land based sources (Wanless, 2009). There is only a small natural supply of this sand, not enough to satisfy the needs of the many nourishment projects that have and will occur. Portions of Florida are running out of compatible sand—the estimated beach-compatible supply will last only a few more years in some locations (K. Lindeman, personal communication, August 16, 2011). In spite of this limited supply, Florida continues to use beach nourishment as the preferred erosion control option, due to pressure from the tourism industry, lobbying by groups such as the American Shore and Beach Preservation Association, and denial of climate change and its effects on the beach.

Many of Florida’s beach nourishment projects have had unpleasant results for beach ecology. One significant case with a blatant disregard for beach ecology is the recent nourishment of Phipps Ocean Park beach in Palm Beach. This project was completed in 2006 and was ecologically incompatible from the start.

The nourishment project itself was very big, covering a long stretch of beach and using a large volume of sand. When implemented, the project used 1.2 million cubic yards of sediment dredged from offshore to fill a 1.4 mile stretch of beach (Applied Technology & Management, 2010). Organisms that live on the sandy beach are biologically adapted to survive a wide range of conditions, including the movement of sand. However, the vast majority of beach organisms cannot survive the extreme burial depths caused by nourishment projects (Speybroeck et al., 2006) Scientific studies have shown that the burial of sand crabs and beach clams during beach nourishment projects sharply depressed their population numbers even 10 weeks after the project (Peterson, Hickerson, & Johnson, 2000). These organisms are simply not adapted to survive the sudden dumping of several feet of sand on top of them. Nourishment projects that cover a larger area, such as the Phipps Beach project, also generally have more severe consequences for the beach ecosystem. Projects that cover a large area take much longer for beach organisms to recolonize than smaller scaled projects (Greene, 2002). Therefore, the size of the project and volume of sand alone probably depressed population levels on the beach for several months.

Another significant problem with this nourishment project was the type of sand that was used. This sand was dredged up from an offshore sand bar, which has a very different kind of sand that that naturally found on Florida’s beaches. Changing the sand’s size, color, shape, or composition alters the habitat, decreasing the ability of organisms to survive. Sand coarser than the native sand results in decreased abundance of invertebrates (Peterson, Bishop, Johnson, D’Anna, & Manning, 2006; Colosio, Abbiati, & Airoldi, 2007). Sand that is too fine, on the other hand, also causes decreased species abundance and diversity (Herrier et al. Eds., 2005). Fine sediment will also remain suspended in the water, making filter feeding more difficult for sessile invertebrates and decreasing the ability of surf fish to see their food (Peterson & Manning, 2001). In the case of Phipps Beach, the project received permission to use a higher amount of fine sediment and gravel than limited by state regulations (Florida Department of Environmental Protection (FDEP, 2002). This higher level of fine material was allowed even though much of the sand within regulation grain size would break down into fine particles when exposed to the dynamic physical forces on the beach.

In addition to the difference in grain size, the dredged sand had a different composition from the native beach sand. In southeast Florida, the native beach sand originated on land and is composed of a quartz-carbonate mixture. However, much of the sand that is dredged up from offshore marine areas to use for beach nourishment is very different, composed predominantly of carbonate skeletal fragments with delicate, fragile designs (Wanless, 2009). These fragments readily break down into fine sediments when exposed to wave energy, weathering into an unsuitably small sand size for the beach. This incompatible sand did not survive the natural forces on the beach. It lifted up into the air with gentle breezes, and ocean waves pulled the sand off the beach, creating black rivers with the longshore current that traveled south to impact adjacent hard bottom and beach habitats. In addition, a couple of tropical storms that year eroded the beach extensively. Within a year, the new sand had washed off the beach, eliminating any positive effects of the nourishment (E. Canales, personal communication, August 19, 2011).

The new sand was also the wrong color: a gray-black instead of tawny brown. Even a change in sand color can change important ecological functions. For example, the gender of turtles is influenced by the temperature of the sand in which the embryos develop. Darker sand will be warmer, and will cause a disproportionate number of eggs to develop as females. A change in sand temperature can also affect the physiology of smaller invertebrates, so that they have to work harder to burrow in the sand. This pressure can make survival more difficult, ultimately decreasing the number of living organisms on the beach.

Other sand composition incompatibilities can negatively affect the beach ecosystem. Sediments that contain contaminants are also unsuitable, as the toxic material will negatively impact the organisms that live on the beach. Sand with a large amount of shell fragments decreases burrowing ability and impedes the foraging behavior of surf fish and shore birds (Peterson & Manning, 2001; Peterson et al. 2006). Cementation of the sand sometimes also occurs when the sand contains large amounts of dissolved shell fragments, causing a hard, cement-like layer on the top of the sand (Van der Wal, 1998 as cited in Speybroeck et al., 2006). Animals are not able to break through this layer, and will remain trapped under the sand or be unable to forage at the surface.

The morphological profile of the beach created by a nourishment project also matters, and it was a problem at Phipps Beach. Many construction projects create a beach profile much different than the original beach, which can result in a permanent shift in the biological community structure (Speybroeck et al., 2006). The spatial pattern of beach organisms depends greatly on the native slope of the beach, so a significant disturbance in this profile results in a significant disturbance in beach ecology. Furthermore, a nourished beach will often form a scarp, or steep drop, at the water’s edge for several months before the new sediment equilibrium is reached. The scarp can be several feet high, making it too difficult for nesting sea turtles to climb onto the beach (Ecological Associates, Inc., 1999). After the sand was placed at Phipps Beach, wave impact created steep, five or six foot tall scarps. A more carefully designed project may have minimized the scarp height, making the beach more compatible for animals, not to mention safer for people.

Other aspects of the design and implementation of beach nourishment projects can also have serious effects on beach ecology. For example, the timing of a project is important: conducting a beach nourishment project after the warm season has started will adversely affect recolonization rates by certain organisms such as sand crabs (Peterson et al., 2000). Generally speaking, a nourishment project carried out in the spring will have much more devastating effects to beach ecology than a project carried out in the winter. Another potential problem is compaction: newly placed sand on the beach usually becomes compacted unless it is tilled immediately after placement. Densely packed sand makes it more difficult for sea turtles to dig their nests and decreases the burrowing ability of invertebrates (Ecological Associates, Inc., 1999; Speybroeck et al., 2006). Finally, the construction activities themselves can also have a direct negative effect, scaring away foraging birds and destroying dune vegetation (Speybroeck et al. 2006). A beach nourishment project that is designed without considering this myriad of potential effects will undoubtedly severely impact the beach ecosystem.

Occasionally, beach nourishment can benefit particular aspects of beach ecology. For example, sea turtles can benefit from beach nourishment when the only other option would be to let the beach disappear entirely. In this case, nourishment helps to maintain the presence of essential nesting habitat (G. Appelson, personal communication, August 18, 2011). It has also been shown that horseshoe crabs may enjoy increased nesting success from a specifically designed nourishment project (Smith et al. 2002). These organisms benefit from an addition of sand when the status quo means that they cannot nest at all. Perhaps if Phipps Beach had not been nourished, it might have disappeared altogether. However, if the goal of the project was to improve habitat for sensitive species like shorebirds, it should have been designed more with ecology in mind.

Finally, the biological monitoring performed after this project did not capture any of the disastrous effects that likely occurred on the beach ecosystem, in the short term or the long term. The final biological monitoring report only discusses effects on the nearshore hard bottom community and the reefs near the dredge site (FDEP, 2006). Apparently, this project did not monitor the sandy beach.

While there are many short-term effects on beach ecology as described in the case above, it is unclear how well the ecosystem will recover from the stress of beach nourishment over the long term. Much of the earlier literature, and a few more recent studies, suggest that the ecosystem is highly resilient and recovers fully within a year of the beach nourishment project (Greene, 2002). However, several recent studies show that this may not be true, and that effects on the beach ecosystem may last much longer than currently believed (Colosio et al., 2007; Peterson et al., 2000). In addition, no research has been completed to assess the long-term effects of beach nourishment or the cumulative effects of multiple projects over larger spatial and temporal scales (Nordstrom, 2005). More work needs to be done to better understand the extent of ecological damage from these projects over time.

Unfortunately, the disregard of sandy beach ecology evident in the Phipps Beach nourishment project is not unusual for the state. Nourishment projects in Broward County, for example, have a history of using incompatible sediments (Wanless, 2009). Considering the state’s minimal supply of useable sand, this problem will only get worse as time goes on. Florida’s Department of Environmental Protection plays a significant part in projects’ poor sediment choices. The state has specific rules for beach nourishment projects, including a requirement to sieve potential sediment to determine whether it falls within size standards (FDEP, 2001). However, fragile offshore sediments will often pass the dry sieve test, but break down and become too fine when exposed on the beach (Wanless, 2009). In addition, the state has recently redefined their rules to allow contaminated sand to be used (Littlejohn, 2011). This type of leadership only exacerbates the lack of consideration of ecological impacts. Poor post-construction biological monitoring also continues to be a widespread issue. If completed at all for the sandy beach, monitoring is done more often than not with poor experimental and statistical design and conclusions that are not well supported by data (Peterson & Bishop, 2005). Nourishment projects in Florida, and elsewhere, need to start using higher standards in their design, implementation, and ecological monitoring.

Best Management Practices

Damage to the sandy beach ecosystem cannot be avoided completely in nourishment projects, but it can be decreased significantly with careful planning. A proposed set of best management practices is outlined below, covering the elements of sediment choice, timing, sand placement methods, site-based design, monitoring, and minimizing conflicts of interest.

  1. Sediment choice: the sediment used should be as close as possible to the native sand, in terms of grain size distribution, color, and composition. Sand should be pre-tested wet in a tumbler to determine how it will behave in the presence of wave energy (Wanless, 2009). Sand should be free of contaminants and have very low proportion of shell fragments.
  2. Timing: The project should be completed before the start of the warm season to improve chances of invertebrate recolonization. Project implementation should be avoided at times that coincide with critical life stages of sensitive species, such as sea turtle or piping plover nesting seasons (Speybroeck et al., 2006).
  3. Sand placement methods: The sand should be placed to mimic the natural beach morphology so that the sediment equilibrium is reached quickly. Sea turtle nesting beaches should have a narrow and steep profile, with a dune feature on the back beach (G. Appelson, personal communication, August 18, 2011). In order to minimize impacts of direct burial, large nourishment projects should be broken into smaller project zones interspersed with untouched beach to facilitate recolonization of infauna, especially if natural conditions, such as weak longshore currents, do not allow for easy recolonization (Speybroeck et al., 2006). Alternately, large projects can be broken up into several smaller projects that each add only a thin layer of sand on the beach, decreasing the chances of infauna mortality. Finally, sand should be tilled immediately after placement to avoid compaction (Ecological Associates, 1999).
  4. Site-based design: Each beach is different, so each project should be designed individually with that beach’s unique features in mind. The project should accommodate the sensitive and valuable natural resources particular to that beach (Speybroeck et al., 2006).
  5. Monitoring: Ecological monitoring should be conducted before, during, and after construction to best understand the extent to which the beach ecosystem changes. Monitoring should also continue well after project completion to understand long-term effects of this anthropogenic disturbance, as well as cumulative effects of multiple nourishment projects. Scientists should use a scientifically and statistically robust monitoring design that looks at multiple indicators of beach ecosystem health. Analysis of data should include a test of statistical power (Peterson & Manning, 2001).
  6. Minimizing conflicts of interest: The project design period should be transparent and include opportunities for public comment. The permitting process should be as free of conflict of interest as possible. Finally, ecological monitoring should be conducted objectively and as independently as possible from those who gain a profit from the project (K. Lindeman, personal communication, August 16, 2011).



Key Concepts

  • Beach nourishment can have a plethora of short-term negative effects on beach ecology, along with likely long-term and cumulative effects.
  • Positive effects on beach ecology are generally limited to creating nesting habitat for species such as sea turtles or horseshoe crabs when the alternate option would be no habitat at all.
  • A nourishment project at Phipps Ocean Beach Park in Florida shows how devastating the effects can be when beach ecology is not taken into consideration.
  • Negative effects on beach ecology can be minimized by following a set of best management practices that include proper sediment choice, timing, spatial implementation, site-based design, ecological monitoring, and minimizing conflicts of interest.



Sources

Applied Technology & Management. (2010). Phipps ocean park (reach 7) beach restoration and dune construction project third year post-construction physical monitoring report. Town of Palm Beach, Fl.

Colosio, F., Abbiati, M., & Airoldi, L. (2007). Effects of beach nourishment on sediments and benthic assemblages. Marine Pollution Bulletin, 54, 1197-1206.

Ecological Associates, Inc. (1999). Martin county beach nourishment project: sea turtle monitoring and studies 1997 annual report and final assessment. Jensen Beach, FL: Ernest R. G. & Martin R. E.

Florida Department of Environmental Protection. (2001). Rules and procedures for application for coastal construction permits (FDEP Rules chapter 62B-41, section (2)(j)).

Florida Department of Environmental Protection. (2002). Notice of final order (FDEP variance no. 0165332-002-EV). Tallahasee, FL: Twin Towers Office Building.

Florida Department of Environmental Protection. (2006). Consolidated joint coastal permit and sovereign submerged lands joint authorization (FDEP permit no. 0165332-006-JC). Tallahassee, FL: Marjory Stoneman Douglas Building.

Greene, K. (2002). Beach nourishment: a review of the biological and physical impacts. Atlantic States Marine Fisheries Commission. ASMFC Habitat Management Series #7. Washington, DC.

Herrier, J. L., Mees, J., Salman, A., Seys, J., Van Nieuwenhuyse H., & Dobbelaere, I. (2005). How may beach nourishment affect the sandy beach ecosystem? The case of belgian beaches. Proceedings ‘Dunes and Estuaries 2005’ – International Conference on Nature Restoration Practices in European Coastal Habitats, Koksijde, Belgium, 19-23 September 2005. VLIZ Special Publication 19.

Littlejohn, J. (2011). Memorandum: Beach program improvements (Florida Department of Environmental Protection).

Nordstrom, K. F. (2005). Beach nourishment and coastal habitats: research needs to improve compatibility. Restoration Ecology, 13(1), 215-222.

Peterson, C. H. & Bishop, M. J. (2005). Assessing the environmental impacts of beach nourishment. BioScience, 55(10), 887-896.

Peterson, C. H., Bishop, M. J., Johnson, G. A., D’Anna, L. M., & Manning, L. M. (2006). Exploiting beach filling as an unaffordable experiment: benthic intertidal impacts propagating upwards to shorebirds. Journal of Experimental Marine Biology and Ecology, 338, 205-221.

Peterson, C. H., Hickerson, D. H., Johnson, G. G. (2000). Short-term consequences of nourishment and bulldozing on the dominant large invertebates of a sandy beach. Journal of Coastal Research, 16(2), 368-378.

Peterson, C. H., & Manning, L. (2001). How beach nourishment affects the habitat value of intertidal beach prey for surf fish and shorebirds and why uncertainty still exists. Proceedings of the Coastal Ecosystems and Federal Activities Technical Training Symposium, August 20-22, 2001.

Smith, D., Jackson, N., Love, S., Nordstrom, K., Weber, R., & Carter, D. (2002). Beach nourishment on delaware bay beaches to restore habitat for horseshoe crab spawning and shorebird foraging (Prepared for Maria Trabka, The Nature Conservancy, Delaware Bayshore Office). Wilmington, DE.

Speybroeck, J., Bonte, D., Courtens, W., Gheskiere, T., Grootaert, P., Maelfait, J., Mathys, M., Provoost, S., Sabbe, K., Stienen, E. W., Van Lancker, V., Vincx, M., & Degraer, S. (2006). Beach nourishment: an ecologically sound defence alternative? a review. Aquatic Conserv: Mar. Freshw. Ecosyst., 16, 419-435.

Wanless, H.R. (2009). A history of poor economic and environmental renourishment decisions in broward county, florida. In Kelley, J.T., Pilkey, O.H., and Cooper, J.A.G., (Eds.), America’s Most Vulnerable Coastal Communities: Geological Society of America Special Paper 460, (111–119). doi: 10.1130/2009.2460(07)

The Way Forward: Ecological Indicators for Sandy Beach Management

In the future, comprehensive coastal management strategies will include evaluation of the ecological state of sandy beaches and use this information to direct management decisions. Olympic National Park in Washington State is already implementing such a strategy for its sandy beaches, providing an example for state coastal management around the nation.

Ecological indicators are a vital component of a sound environmental management program. An indicator is a specific ecosystem component that when measured, gives an idea of the state of ecological health. For example, immobile invertebrates may be thought of as a good indicator species because they are particularly sensitive to environmental stressors and cannot run away from them. A significant change in the environment, such as an increase in temperature or the presence of a toxic substance, will reflect in a change in the sessile invertebrate community. Monitoring for a set of ecosystem indicators over a long period of time helps managers understand the baseline ecological status and reveals how the health of the ecosystem is changing over time. Ultimately, indicators can be used to understand the ecological effects of management choices and enables future actions to more accurately create the desired level of ecological health.

Implementing a monitoring system with ecological indicators takes more effort than doing nothing, but is worth the investment because beach ecosystems have value to society. In addition to the intrinsic value and beauty of the life that has evolved on the sandy beach, the beach ecosystem provides practical services that are valuable to our society. These services include, among many, providing a natural buffer against storm events, creating a home for species such as birds and elephant seals that people love to watch, and cycling nutrients that help to feed nearshore marine habitats, which in turn provide us food (Defeo et al., 2009; Dugan, Hubbard, Page, & Schimel, 2011). If a beach has degraded below a certain level of ecological health, it will not be able to provide us with these services to the degree that we would like. Using a set of indicators to measure ecosystem health will inform us about how our current management practices are affecting beach ecology, and help us to design better practices that will sustain those natural services that we value.

Olympic National Park has implemented such a monitoring program to assess the ecological health of its sandy beaches. The park has 73 miles of coastline made up of rocky shores and sandy beaches. The long-term ecological monitoring program was first started in 2005, and beach monitoring has been conducted annually since then. The monitoring program is designed to measure how the ecosystem responds to anthropogenic stressors particular to that stretch of coastline. These stressors include harvest, human trampling, toxic chemical spills, climate change, nutrient enrichment, hydrologic manipulation, exotic species, and aquaculture (Jenkins, Woodward, & Schreiner, 2003). The ecological indicators chosen to measure the effects of these stressors are: water temperature, species composition and abundance of intertidal invertebrates, sediment size, and beach morphological profile. The Olympic National Park coast beaches can be broken into four different zones based on temperature and salinity. The monitoring program surveys two beaches in each of the zones, with one beach in the northernmost zone, for a total of seven beaches. The first component of the monitoring system is relatively simple: temperature data loggers have been set up in the mid-intertidal zone to take temperature readings every half hour. This data will help scientists better understand what intertidal organisms experience and whether they are subjected to unusually stressful temperature conditions (S. Fradkin, personal communication, August 30, 2011). The second component of beach monitoring uses annual surveys of the other ecological indicators. Each survey uses three linear transects along the beach that extend about 60 meters from the previous high tide line down to the water’s edge. Every 7.5 meters, a sample of four replicate cores are taken and sieved to examine the species composition and abundance of invertebrate organisms. An additional core is taken back to the lab to measure the sediment size distribution. Finally, elevation is determined at each point along the transect to map out the profile of the beach. These last two measurements will show how beach morphology and sand grain size change over time in response to pressures like stronger, more frequent storms due to climate change (S. Fradkin, personal communication, August 30, 2011). A change in beach morphology and sediment size will lead to a change in the ecological community. Together, all of these indicators provide a good picture of the state of the beach ecosystem.

The Park will soon be able to use the monitoring results to help refine their management plan for the sandy beach. Scientists are currently analyzing the first few years of data to determine the baseline level of ecosystem health as well as any significant trends that could signify influence from human pressures. However, the monitoring program is designed for the long term, and it may still be too soon to identify with certainty any significant trends in beach ecological health. Generally, a minimum of 10 years of monitoring is needed to really understand how healthy the beach ecosystem is and how quickly it is changing (S. Fradkin, personal communication, August 30, 2011).

This program is a great model for the Washington state government, and indeed for all states around the nation, to look to as they move toward ecosystem-based management of sandy beaches and the greater coastal environment. In Washington, the Olympic Coast National Marine Sanctuary has adopted the National Park’s monitoring protocol for beaches on two Native American reservations (L. Antrim, personal communication, August 16, 2011). Washington state has a long-term goal to create an integrated marine spatial management plan that includes using ecological indicators for each marine habitat (Hennessey, Nichols, & the State Ocean Caucus, 2011; Skewgar & Pearson, 2011) The adoption of this or a similar protocol for all of Washington’s beaches will give the state vital information on the relationship of beach ecology to human pressures and to other ecosystems, information that can be used in the design of a marine spatial plan. As of yet, no beach ecosystem monitoring and assessment is being conducted at the state level.

Currently, the vast majority of management decisions concerning the sandy beach take ecology into consideration only minimally; states must take several steps to develop comprehensive beach ecology monitoring systems. Many states monitor only a single ecological indicator on their beaches, such as water quality or counts of endangered shorebirds or turtles. However, this one-dimensional monitoring does not measure the many ecosystem services that the beach provides—a robust system of indicators ought to be used. States also tend to monitor only the effects of individual management projects, such as a beach nourishment project or the erection of a seawall. Monitoring for an individual project does not capture the cumulative and additive stresses of many human actions over larger spatial and temporal scales (Halpern et al., 2008). Monitoring for just one species or just one project will not give an accurate assessment of the true state of beach ecology. Furthermore, the set of indicators should be designed to measure those human pressures particular to each state’s shoreline. Finally, states need to define a “goal status” of ecological health that will best allow the beach to provide its natural services while considering other activities and uses important to the culture and economy. Once this goal is established, the information from ecological monitoring becomes useful by showing how close the state is to achieving its goal, as well as revealing which practices are hindering the state from creating that level of ecological health.

Using indicators to measure beach ecological health is the next step in sandy beach management. Following in the footsteps of Olympic National Park, coastal states can increase their understanding about their beaches and utilize this information to develop sustainable management strategies. The sooner that states incorporate this method into their management plans, the better they will be able to balance the needs of beach and ocean users with the needs of the natural resources on which those people depend.

Key Concepts

  • Design an ecological monitoring system that can measure how the beach ecosystem responds to human pressures particular to your state’s coastline.
  • Complete initial monitoring to determine the baseline level of ecological health.
  • For each beach, decide on the level of ecological health that will contribute to optimal benefits for humans in the long term.
  • Use long-term monitoring to measure changing health of the beach in response to long-term and cumulative pressures.
  • Incorporate information from indicators into a comprehensive ecosystem-based management system, and adjust management practices according to monitoring results


Sources

Defeo, O., McLachlan, A., Schoeman, D. S., Schlacher, T. A., Dugan, J., Jones, A., Lastra, M., & Scapini, F. (2009). Threats to sandy beach ecosystems: a review. Estuarine, Coastal and Shelf Science, 81, 1-12.

Dugan, J., Hubbard, D., Page, H., Schimel, J. (2011). Marine macrophyte wrack inputs and dissolved nutrients in beach sands. Estuaries and Coasts, 34(4), 839-850.

Halpern, B. S., McLeod, K. L., Rosenberg, A. A., & Crowder, L. B. (2008). Managing for cumulative impacts in ecosystem-based management through ocean zoning. Ocean & Coastal Management, 51, 203-211.

Hennessey, J., Nichols, B., & The State Ocean Caucus, Eds. (2011). Marine spatial planning in washington: final report and recommendations of the state ocean caucus to the washington state legislature (Washington Department of Ecology publication No. 10-06-027). Olympia, WA.

Jenkins, K., Woodward, A., & Schreiner, E. (2003). A framework for long-term ecological monitoring in olympic national park: prototype for the coniferous forest biome (USGS/BRD/ITR publication No. 2003-0006). US Department of Interior & USGS. Denver, CO: U.S. Geological Survey, Information Services, Denver Federal Center.

Skewgar, E. & Pearson, S. F., Eds. (2011). State of the washington coast: ecology, management, and research priorities. Washington department of Fish and Wildlife. Olympia, WA.