Category Archives: Saas, Emma

Beach Recovery

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— Written by Emma Saas

In my previous blog post, I explored how beach species might move from one beach to another, especially as their habitat is being lost. Now, I’d like to focus more on the recovery of sandy beach habitats as a whole. A number of stressors affect these narrow areas, including recreation, armoring, sea level rise, and extreme weather conditions.

Recreational activities such as driving on the sand, and preparation for recreational activities such as beach grooming, can lower the biodiversity of a beach drastically. Human impacts do not end there, unfortunately. Coastal armoring is put in place to protect roads, buildings, and homes. All are worthy of protection, as people need places to live and roads to drive on, however the armoring cuts into upper beach habitats. This reduces the amount of room the animals have to move, and as sea levels rise, the beach is narrowed even further. Essentially, the beach habitat is being squeezed and narrowed. Rising sea levels in conjunction with armoring and other stressors contribute to the loss of the upper beach first, which is where we find beach hoppers.

El Niño winters are an example of an extreme weather condition that can wipe out all the sand, fauna, and flora on a beach. Recovery from this type of event can be slow, but it is possible. With restoration efforts, some beaches could potentially slowly recover from all of these stressors. However, an important step in beach conservation is to reduce the initial impact we have on these habitats as much as possible.

From Beach to Beach

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— Written by Emma Saas

Rising sea levels and beach erosion create problems for important intertidal species, such as beach hoppers, normally found on sandy beaches. Their sandy environment is shrinking, and scientists are wondering how well they will find new real estate. The distribution and abundance of different each hopper species may vary among southern California shores, but one can find beach hoppers, such as Megalorchestia corniculata, on many beaches. The dispersal of beach hoppers from beach to beach may be an important factor in the distribution of the four common species.

Yachts are a little bit pricey for our tiny beach hoppers, so how can they move from one beach to the next? The answer may be drift kelp, an important resource for marine environments that is produced by off-shore kelp forests. Beach hoppers can cling to drifting kelp and perhaps use this mechanisms as a lift to new beaches. How well they can cling, however, is an important question. Ideally, beach hoppers may be able to survive rising sea levels by clinging to drift kelp after it washes onto the shore and then leave with it as it floats to its next destination. An added bonus? Kelp is also food for these traveling beach hoppers! They’re able to sustain themselves for free while traveling (personally, Delta charges me excessive amounts for the same thing), which could enhance their survival on longer trips to a new beach.

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Beach hopper climbing in Macrocystis pyrifera, otherwise known as giant
kelp, commonly found on California beaches washing in from the kelp forests

Sea level rise will lead to habitat changes and a requirement for flexibility. According to recent studies, 25% of beaches are eroding worldwide and up to 67% of beaches in southern California could disappear by the end of the century. Creatures who made their homes on sandy beaches will see a significant narrowing of their stomping ground. Their ability to disperse to and from different beaches on kelp may reflect how well they can move around once sea levels are consistently encroaching on their living space.

Calling for a change in our definition of sandy beaches

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— Written by Emma Saas

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Kelp washed up on shore, providing resources for many sandy beach invertebrates

The California coast is world famous for its miles of sandy beaches, sunbathing, beach volleyball, and morning jogs along the water line. Each year, millions of tourists come to enjoy what this state’s shorelines have to offer- and why wouldn’t they? Watching sunsets in bathing suits after a long day of surfing sounds like a pretty postcard worthy vacation. What many tourists -and locals!- don’t always think about,is the fact that beaches are also rich coastal ecosystems. Food webs on beaches depend on subsidies from other marine ecosystems, like kelp forests. On many tourist beaches, beach grooming removes washed up kelp and other organic material from the beaches using large machines. Kelp is food and shelter for many important invertebrates including talitrid amphipods, commonly known as beach hoppers that look like little jumping shrimp.

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Megalorchestia corniculata, a talitrid amphipod, begins burrowing into the sand

Several species of beach hoppers are commonly found on southern California beaches including Megalorchestia corniculata, M. californiana, M. minor, and M. benedicti. All four of these highly mobile crustacean species burrow into the damp sand near the high tide line and emerge to feed on kelp, damp paper, and even cardboard after dark. As vital parts of the beach food web, talitrids are preyed upon by birds and other animals. They are most active at night to avoid becoming an afternoon snack! Deep damp burrows create a cozy place for talitrids to remain safe and out of sight all day long. Unfortunately, widespread destructive practices, such as beach grooming disrupt their burrowing, shelter, and food supply.

 

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Picture of an adorable talitrid amphipod for good measure

This wealth of unique intertidal life found on ungroomed beaches begs the question, what is a pristine sandy beach?  The definition of ‘pristine’ has to cease to be ‘empty combed sand’, and instead turn into ‘healthy ecosystems rich with life’. Global warming threatens our sandy beaches with rising sea level and higher temperatures, beach grooming mechanically removes sustenance and habitat, and humans need to truly realize our impacts on the places we love. For as much as we love our sandy beaches, we do not want to love them to death.