Interrelationship between the horseshoe crab and the red knot as well as other shorebirds
There is a very significant relationship between the red knot birds and the horse-shoe crab, which makes the increased human harvest of the horseshoe crabs a threat to the lives of red knot birds. During the late spring in beaches like Delaware, there is mass mating of the horseshoe crabs (Tsipoura & Burger, 1999). These horseshoe crabs are closely related to scorpions and spiders. During their season of mass mating along exclusive beaches such as Delaware, they are normally joined by many wading shorebirds like the red knots, which dash through the waves in order to feed on the small green eggs of the horseshoe crabs.
The red knot is a type of shorebird that is normally robin-sized. It was recently classified as endangered species under the Endangered Species Act. This bird is one of the long-distance migrants within the animal kingdom. Horseshoe crabs are very essential to the survival of these red knot shorebirds because they provide the food on which they feed. Red knots feed on the eggs of horseshoe crabs (Escudero et al., 2003). Therefore, the red knots solely depend on the eggs of the horseshoe crabs. Horseshoe crabs on the other side, are harvested by the costal watermen is a popular bait. The increased harvest of these horseshoe crabs implies the red knots lack food hence end up dying. These are the interrelationships that have put the two species into jeopardy.
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Importance of their preservation
Red knots and other shorebirds are very significant tourist attractions along the coastal beaches of the country. They are, therefore, a source of foreign exchange for the country. The red knot is actually an endangered species and has to be preserved. Moreover, since its livelihood and survival depends on the existence of the horseshoe crabs, they also have to be preserved. The red knot has naturally been in danger. The fact that red knot shorebirds move in huge flocks together continues to set it for more jeopardy (Fraser et al., 2010). The huge gathering in which the red knot shorebirds move makes it easy for the destruction of their habitats. As a result of these vital statistics, the red knot is now on peril. Its population is greatly diminishing as a result of the increased harvest of the horseshoe crabs to be used as baits for fishing.
Currently, the U.S. Shorebird Conservation Plan has the red knot on its list as a species of high concern, considering the fast trend of declining population of these shorebirds (Niles et al., 2014). Statistics indicate that for the last 20 years, the red knots have been able to fall in number from 100,000 to 15,000. It can be seen that this is a very large loss. Its population has decreased by a whopping 75% since the year 1980 (Schwarz, 2015).
Some of the general reasons for this fall in the number of red knots include the rise of the sea-level and human development of infrastructure and other activities at the coast. This human development along the coastal beaches normally reduces the wintering and migratory habitat of these shorebirds. The major factor behind this fall in the species of the red knot has been the declining population of the horseshoe crabs as a result of massive human harvest. The most interesting feature about the horseshoe crab is its unique blue-blood (Smith et al., 2006). The clotting agent of this blood of the crab, known as lysate is applied in the tests for intravenous drugs for bacteria (Berkson & Shuster, 1999). Every drug has to be tested for the blood of the horseshoe crab before getting into the market. This has created massive harvesting interest for the species.
Actions that should be taken to preserve the horseshoe crabs and the red knot shorebirds and associated rationale
Clear actions have to be taken in order to preserve the two species of horseshoe crabs and the red knot shorebirds. It has to be understood, while the existence of horseshoe crabs may not be of direct value to human beings, the presence of the shorebirds such as red knots along the coastal beaches is very significant for the tourism sector (González et al., 2006). Therefore, the population of the red knot birds must never be under any threat. The reality is that for the red knots to be preserved, the horseshoe crabs have to be protected because of the strong relationship between the two species. The fishing industry has to be regulated so that fishers are not let to use the horseshoe crabs as baits for catching fish. Moreover, the government has to ban fishing activities along the beaches where the red knot shorebirds visit during their migration. With the horseshoe well protected, the red knots will also be preserved and let to survive as they increase in population size.
Lessons
While tackling this topic, I have been able to learn that red knot shorebirds are creatures that may not be directly targeted by human beings, but are highly endangered because of the actions of people on horseshoe crabs. The red knots depend on the eggs of the horseshoe crabs for food hence human harvest indirectly affects the population size of the birds. This is a very important matter because it is about the red knot, which is a very unique shorebird that attracts tourists to the coastal beaches like in Delaware.
References
Berkson, J., & Shuster Jr, C. N. (1999). The horseshoe crab: the battle for a true multiple-use resource. Fisheries , 24 (11), 6-10.
Escudero, A., Abril, A., Murga, M. G., & Hernández, N. A. (2003). Red Knots wintering in Bahía Bustamante, Argentina: are they lost. Wader Study Group Bull , 101 (102), 59-61.
Fraser, J. D., Karpanty, S. M., & Cohen, J. B. (2010). Shorebirds forage disproportionately in horseshoe crab nest depressions. Waterbirds , 33 (1), 96-100.
González, P. M., Baker, A. J., & Echave, M. E. (2006). Annual survival of Red Knots (Calidris canutus rufa) using the San Antonio Oeste stopover site is reduced by domino effects involving late arrival and food depletion in Delaware Bay. El hornero , 21 (02), 109-117.
Niles, L. J., Dey, A. D., & Maslo, B. (2014). Overexploitation of marine species and its consequences for terrestrial biodiversity along coasts. Coastal Conservation , 19 , 347.
Schwarz, S. (2015). Knot Your Average Bird: A Case Study of the Rufa Red Knot in the Face of Climate Change. Animal L. , 22 , 165.
Smith, D. R., Millard, M. J., & Eyler, S. (2006). Abundance of adult horseshoe crabs (Limulus polylphemus) in Delaware Bay estimated from a bay-wide mark-recapture study. Fishery Bulletin , 104 (3), 456-464.
Tsipoura, N., & Burger, J. (1999). Shorebird diet during spring migration stopover on Delaware Bay. Condor , 635-644.
