What is an invertebrate?
The word invertebrate refers to any animal that does not have a notochord, or backbone. Invertebrates are incredibly diverse. There is just one phylum of vertebrates (animals with backbones), and there are 34 phyla of invertebrates.
Pacific Marine Invertebrates
Pacific marine invertebrates can be divided into a number of major groups and inhabit both intertidal and subtidal zones. They have been around for a very long time, some as long as 500 million years. Despite this, we know scarcely little about some of the most abundant animals on our planet. Some of the major groups include:
Echinoderms: This group includes sea stars, sea cucumbers, sea urchins and sand dollars.
Cnidarians: This large group includes sea anemones, coral, and jellies
Arthropods: This group, one of the dominant forms of the life on Earth, and certainly not limited to the ocean, includes crustaceans (crabs, shrimp, lobster) as well as barnacles
Molluscs: Also not limited to the ocean, this diverse group includes cuttlefish, octopus, squid, clams, snails, nudibranchs, chitons, mussels and oysters
Sea star wasting disease
July 2013 marked the beginning of a mass die-off of various species of sea stars off the Northwest coast of United States and the West coast of British Columbia. The source was unknown, and was given the name "sea star wasting disease". The cause is not yet fully understood, and it is believed to be the result of multiple factors, including climate change, and oceanic warming in particular. The species most affected is the sunflower sea star, the world's largest. It has seen it's numbers reduced by between 80-100% over a range of roughly 2000 km. There have been sea star wasting events in the past, but nothing on this scale, and with such large mortality. It is a reminder that marine invertebrates are just as vulnerable to the effects of climate change and environmental degradation as other marine species.
Find out more about sea star wasting disease here.
Find out more about invertebrates