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Save the Red Knot - Halt the Harvest
Three cheers for the New Jersey Department of Environmental Protection! Officials there are pushing to extend the existing two-year moratorium on horseshoe crab harvesting in the state to help the red knot rebound from the brink of extinction. Let officials know you are behind them. Each spring, red knots make a vital stop on the Delaware Bay along their migratory route, spending about two weeks fattening up on protein-rich horseshoe crab eggs before making the last leg of their journey. If they aren’t able to find enough horseshoe crab eggs to eat, they will be too weak to breed when they finally arrive at their Arctic breeding grounds in northern Canada. Unfortunately, horseshoe crabs have long been victims of overfishing due to increased demand for eel and conch (horseshoe crabs are used as bait). In 2005, New Jersey officials put a hold on the state’s horseshoe crab harvest in order to increase the supply of eggs on the beach. And now that the moratorium has expired, they are working to pass a new regulation to extend it. Records show that the red knot population is in worse shape now than it was two years ago -- there are fewer birds and they’re having more trouble gaining the weight they need to migrate and breed successfully. The good news is that a moratorium can work -- horseshoe crabs have been bouncing back since the harvesting ban was instituted. But it can only work if it is left in place long enough. Since horseshoe crabs are long-lived and take years to reach breeding age, officials recognize the need for long-term recovery efforts to ensure that the moratorium is in place long enough to make a real difference for these struggling birds. It’s clear that the red knot is in crisis -- the rare rufa subspecies has plummeted from 100,000 a decade ago to approximately 33,000 today. Scientists predict that they could go extinct within five years if drastic measures aren’t taken! Thankfully, New Jersey is taking unprecedented steps to save them. Show your support for their efforts. I hope you'll send a message of thanks to state officials for taking the initiative to extend their efforts to save the struggling shorebirds. The deadline for comments on this proposal is coming up on this Friday, February 1st, so please take action today!
Dear [ Decision Maker ] , As a conservation-minded New Jersey resident, I am impressed by the leadership your agency has shown in the struggle to recover red knots and strongly support your proposal to extend the moratorium on the harvest of horseshoe crabs in our state to allow their recovery to continue. As you know, the horseshoe crab's protein-rich eggs are a vital food source for these threatened shorebirds and several other migratory bird populations that depend upon finding an abundant supply in the Delaware Bay on their long-distance migration routes. Records show that the red knot population is in worse shape now than it was two years ago -- there are fewer birds, and they're having more trouble gaining the weight they need to migrate and breed successfully. Thankfully, the moratorium you put in place two years ago has allowed our local horseshoe crab population to rebound, but there continues to be a serious shortage of eggs. Since horseshoe crabs are long-lived and take years to reach breeding age, it is important to keep the moratorium in place long enough to make a real difference for these struggling birds. It's clear that the red knot is in crisis -- the rare rufa subspecies has plummeted from 100,000 a decade ago to approximately 33,000 today. Scientists predict that they could go extinct within five years if drastic measures aren't taken. Fortunately, New Jersey is taking unprecedented steps to save these rare shorebirds. And with the state of Delaware's recent decision to allow 100,000 male horseshoe crabs to be harvested this year, extending New Jersey's moratorium is all the more important. Thank you for continuing to go beyond the call of duty to help save this struggling species.
Sincerely, |
Campaign Launched: |
| Background Information |
The purpose of the two-year moratorium on the harvesting of horseshoe crabs was to improve conditions for the Red Knot (Calidris canutus rufa) and other shorebirds that migrate through Delaware Bay in the spring. These birds feed on horseshoe crab eggs to restore their energy supplies and complete their journey to the arctic breeding grounds. Red Knots migrate north from the southernmost tip of South America at Tierra del Fuego, undertaking shorter flights along the Eastern coast of South America and finally a direct longer flight from the coast of Brazil to Delaware Bay. The Delaware Bay stopover is critical, as the birds arrive in an already depleted condition and need to gain weight rapidly within an approximately two week period before continuing on to the breeding grounds on another non-stop flight. Red knots must carry sufficient energy reserves to survive the flight to the Arctic and to be able to breed once they arrive.
Red Knots congregate on the beaches of Delaware Bay to feed on horseshoe crab eggs and restore their energy supplies. Stable isotope diet tracking and captive feeding trials as well as field diet studies reveal that crab eggs are a critical food resource to migratory shorebirds along the east coast of North America that allows rapid migratory fattening (Tsipoura and Burger 1999, Haramis et al. 2007). Feeding on the horseshoe crab eggs is, therefore, a critical component of the survival of Red Knots and other shorebird populations.
The number of Red Knots that come together on Delaware Bay beaches as well as those wintering in South America have experienced dramatic population declines from their numbers in the 80s and the 90s (Morrison et al. 1998, Baker et al. 2004, Morrison et al. 2004, Niles et al. 2007). Demographic models show that low adult survival was the reason behind these populations declines (Baker et al. 2004). This is in full agreement with recent research that shows that only a small proportion of Red Knots, only 27% of the birds passing through Delaware Bay, are able to consume enough horseshoe crab eggs during their Delaware Bay stopover to reach the body mass required to successfully complete the last leg of their migration. Bird mortality is expected to be high when the birds have not achieved the physiological conditions necessary to undertake their migratory flight. Furthermore, the other parameter of population stability, breeding success, would also be expected to have declined substantially if birds arrive on the breeding grounds in poor physiological condition.
Therefore, without adequate horseshoe crab eggs, the predominant food resource for shorebirds in Delaware Bay, shorebird populations are at risk. And, in fact, concentrations of the eggs have declined significantly since the early 90s. The moratorium on horseshoe crab harvesting was imposed to improve conditions for shorebirds by reversing declines in the horseshoe crab populations. Since the horseshoe crab in long-lived species that takes up to 10 years to reach sexual maturity, a 2-yr moratorium is not sufficient to either assess the success of these restrictions on increasing horseshoe crab populations and egg concentrations on beaches or to determine whether those increases will be sustainable.
Proposals to allow harvesting of 100,000 male horseshoe crabs instead of a moratorium are based on very limited scientific knowledge of the population structure and reproductive dynamics of this species. While more males than females may be present on the spawning beaches at any one time, this does not represent the population sex ratios during the non-breeding season. Furthermore, the excess 'satellite' males may fertilize a significant proportion of the eggs (Brockman et al. 2000). There is no biological support that harvesting the male horseshoe crabs will not have a significant impact on their populations.
Furthermore, nature-based tourism on the Delaware Bay dependent on shorebirds and horseshoe crabs is a large and thriving industry. A 2000 report to the NJ Division of Fish & Wildlife valued the Delaware Bay ecotourism between $16 and 34 million annually. This vibrant economic sector is being threatened by the overharvest of horseshoe crabs and subsequent collapse of the Delaware Bay shorebird stopover.
Considering the importance of the horseshoe crabs for the entire population of the Red Knot as well as other shorebird species, risk averse approach is mandated to manage and protect this resource. We therefore strongly support the moratorium as the only ecologically sound, risk averse approach.
