Monday, September 11, 2017

Minding the Fisheries - Tides

By Rebecca Proulx, communications intern

Save The Bay’s mission to protect and improve Narragansett Bay goes well beyond our fight for water quality sufficient to realize our vision for a fully swimmable, fishable Bay. Our mission extends into the realm of species protection as well, because native many native species play important and interdependent roles in both water quality and ecosystem health. In recent years, we’ve been focused on four species: the Atlantic menhaden, river herring, American eel and horseshoe crabs.

The Most Important Fish in the Sea
The Atlantic menhaden is called the “most important fish in the sea.” A member of the herring family, the species is well known as a critical food source for some of America’s most precious ocean wildlife, including humpback whales and osprey. Menhaden are a key food group for many fish at the heart of our local recreational fishing industry, including striped bass and bluefish. But this tiny fish also plays an immense role in the ecosystems and water quality of Narragansett Bay and its watershed.

Above: Save The Bay docents teach visitors 

at the Exploration Center & Aquarium about 
the importance of horseshoe crabs. 
Top right: Atlantic menhaden. 
A single menhaden can clean up to four gallons of water per minute as it grazes on algae and other plankton organisms. Called filter feeders, menhaden in healthy populations consume large volumes of plankton, helping to remove excess nutrients from the water, preventing excessive algae growth, and ensuring the water has enough sunlight and oxygen to maintain marine life below the surface.

Save The Bay advocates for a robust and sustainable menhaden population, lest we lose the valuable water quality and ecosystem impacts of these tiny fish. “We must shift the fisheries’ focus from taking just enough menhaden to avoid wiping out the population, to leaving a substantial population not only for future harvest but for the filtration of our water,” says Save The Bay Executive Director Jonathan Stone.

Unfortunately, what seems broadly obvious is a daunting challenge, because menhaden are the most heavily com-mercially-fished species in the Atlantic region. They are factory-processed for oil, protein meal, and solubles, and used for bait in both commercial and recreational fishing. While the Rhode Island Department of Environmental Management (DEM) Fish and Wildlife Division has made strides in recent years to tighten regulations on commercial fishing in the area, menhaden are persistently overfished by commercial interests in other areas. In the Chesapeake Bay region, for example, Omega Protein, a single company in Reedville, Virginia, currently dominates the market, controlling 85 percent of the available catch.

By promoting an ecosystem-based approach to preserving the resources of Narragansett Bay, Save The Bay has been pushing for stricter catch regulations to support not only water quality, but also predator species up the food chain. According to Stone, Save The Bay has “made written proposals to the R.I. Marine Fisheries Commission, advocating for the elimination of all purse-seining in local waters and an increase in the baseline threshold of menhaden biomass observed in state waters before commercial harvest can commence.” We have also taken the issue to the Atlantic States Marine Fisheries Commission, according to Stone.

Save The Bay has also been working to obtain funding for a research team to collect updated evidence on menhaden’s role in removing and transporting nitrogen from the water column. “This study could have profound implications up and down the East Coast given that menhaden act as a primary food source to countless fish and bird species and also function in the vital role as a filter fish to preserve the cleanliness of our waters, two jobs that should be of concern to all of us,” said Stone.

The Oldest Creature on Earth
Horseshoe crabs are among the oldest unchanged living species on earth and culturally iconic to Narragansett Bay. They are important commercially as bait for eel and conch fisheries, an important food source for many migratory shorebirds and finfish, and vital to Bay and salt pond ecosystems. T h e s e prehistoric arthropods also play a significant role in the biomedical industry, because their unique, bright blue blood has remarkable antibacterial properties used to detect dangerous bacteria in intravenous solutions, medical devices and vaccines.

Overharvesting, however, threatens to reverse 450 million years of survival for the Atlantic horseshoe crab. Its population in Rhode Island has dramatically declined since the 1970s and still has not recovered. Nearly 20 years ago, Save The Bay advocated for stricter limits on harvesting horseshoe crabs, based on strong evidence of overfishing, and has enthusiastically played an active role in preserving the species ever since. Unfortunately, the species failed to recover after DEM first imposed conservation measures in 2000.

Save The Bay has continued to lobby for stricter horseshoe crab regulations, and this winter, the R.I. Department of Environmental Management’s Division of Fish and Wildlife proposed new changes, to try, once again, to reverse the decline in population. Our team sprang into action, not only to support DEM’s efforts against opposition, but also to call for an even longer spawning closure, taking into account new data about climate change impacts on the horseshoe crab spawning season. We submitted two letters to DEM urging tighter restrictions on the horseshoe crab fishery. We met with DEM staff, and participated in a public comment meeting, a public hearing, and a R.I. Marine Fisheries council meeting. And we issued a press release drawing media and public attention to the importance of protecting this fishery.

As it now stands, DEM is enforcing stricter catch limits on crabs per person and requiring commercial fisheries to report all their catches. DEM also extended the spawning closure period from just a few days to four weeks, from May 1 to May 31, so the crabs can spawn throughout the month of May without threat of being harvested for bait. While this isn’t the full six weeks we asked for, “we consider the latest regulatory changes an important step in the right direction, but will continue to advocate for stricter limits in the coming years,” said Stone.

Research has found that horseshoe crab spawning appears to be triggered more by water temperature than by the highest tides associated with the new and full moons. “In 2014, warmer water temperatures triggered horseshoe crab spawning in April, and the bait quota was exhausted by the beginning of May, prior to the existing regulatory spawning closures. Even the new, longer closure period will not fully protect spawning crabs from harvest,” Stone said. “DEM must extend the closure into April if it is to fulfill its statutory duty to protect the species and allow it to regenerate.”

Where the River Meets the Bay
Further up the watershed, the American eel and river herring populations suffer not only from overfishing and poaching, but also from loss of spawning habitat resulting from some 600 dams in Rhode Island and more than 3,000 in Massachusetts.
This fish ladder in Rehoboth, Massachusetts, allows river herring 
and shad to reach Shad Factory Pond.
American eels are a highly valued member of the food web, an important food source for numerous fish and birds, such as striped bass and osprey. They are catadromous fish, which means they live in our freshwater rivers and migrate to the Sargasso Sea in the middle of the Atlantic Ocean to spawn. The juveniles return each spring to repeat the cycle. The anadromous river herring, on the other hand, spend their lives in the sea and return to our freshwater rivers to spawn. As forage fish, river herring help keep the Bay clean by consuming plankton, and, like the American eel, are also a main food group for ospreys, striped bass and other predators. In order to fulfill their natural benefit to our ecosystem, however, these fish must be able to access the habitat important to their life cycles. No matter which direction the fish are going, dam construction, culverts and habitat degradation have taken a toll on both herring and eel populations.

Save The Bay is conducting an eel monitoring project this spring at the Rising Sun Mills to be vigilant in conserving their numbers. While overall, the American eel population in Rhode Island is solid, “the species is much smaller than it has been in years past,” says Save The Bay Riverkeeper Rachel Calabro. Calabro says that Save TheBay will be working with the DEM Fish and Wildlife Division on the project, using ramps to collect and count the eels.

Working with partners in both Rhode Island and Massachusetts, Save The Bay has endeavored to build fish ladders and remove dams wherever possible to restore these historically and ecologically important species to their natural habitat. “On the lower part of the Ten Mile River, for example, we built three fish ladders that opened up 340 acres of spawning habitat that can support more then 200,000 herring,” Calabro said. Along the Pawcatuck River, project partners removed the Lower Shannock Falls Dam, and in the Taunton River watershed, which has the region’s largest herring run, we have worked with the Massachusetts Division of Ecological Restoration on several dam removal projects.

Our mission is to protect and improve Narragansett Bay. Our ecosystem-based approach to doing that means we have cultivated a rich history in championing the full array of interactions and interdependencies within Narragansett Bay that contribute to water quality. Menhaden, river herring, American eel and horseshoe crabs are all important species in our mission to achieve a swimmable, fishable, healthy Narragansett Bay. We will continue to fight for them as strongly as we have fought many battles since 1970.

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