Horseshoe crab all but end the practice of blood harvesting from horseshoe crabs. Horseshoe crabs are used as bait to fish for eels (mostly in the United States) and whelk, or conch. However, fishing with horseshoe crab was banned indefinitely in New Jersey in 2008 with a moratorium on harvesting to protect the red knot wading bird, which eats the crab's eggs. A moratorium was restricted to male crabs in Delaware, and a permanent moratorium is in effect in South Carolina. The eggs are eaten in parts of Southeast Asia and China. A low horseshoe crab population in the Delaware Bay is
Common species because common species shape ecosystems, contribute disproportionately to ecosystem functioning, and can show rapid population declines, conservation should look more closely at how the trade-off between species extinctions and the depletion of populations. Common species Common species and uncommon species are designations used in ecology to describe the population status of a species. Commonness is closely related to abundance. Abundance refers to the frequency with which a species is found in controlled samples; in contrast, species are defined as common or uncommon based on their overall presence in the environment. A species may be locally abundant without being common. However,