Crayfish & Lobsters
There are currently around 590 known species of freshwater crayfish, and nearly 250 known species of marine lobster. Comprehensive Red List assessments of these species were carried out between 2009 and 2011. The crayfish were assessed in collaboration with the IUCN SSC Freshwater Crabs & Crayfish Specialist Group.
Lobsters are marine crustaceans which start life at the top of the water column, migrating to the bottom to hide under rocks or in burrows when a few weeks old. They live on a broad diet of up to 100 species a day, thus controlling the abundance of many species through predation. Crayfish are freshwater crustaceans which inhabit a range of wetland habitats where they prey on larvae, snails and small fish as well as feeding on detritus and algae. They interact at many trophic levels and regulate many processes including nutrient cycling.
65% of lobsters are classified as Least Concern or Near Threatened. Only one species is listed as Vulnerable. However, almost 35% are Data Deficient which means that the level of threat may have been considerably underestimated. For crayfish, 571 species have been published on the Red List so far. 31% of these are thought to be threatened. Nearly 80% of Euastacus species (Spiny crayfish) are currently threatened by climate change, introduced species, habitat degradation and loss. The introduction of the American Signal crayfish into European waterways has resulted in significant declines in European crayfish species such as the Noble crayfish due to competition and disease transmission.