Sea Star Diversity

By The Marine Detective on December 28, 2020

Diversity matters. Language matters. I suspect you agree. ☺️

In this case it’s about sea stars. I am sharing with you because you are an important audience to help increase understanding.

Just off our coast, there are 31 species of sea star in the Class “Asteroidea”. I hope my compilation below gives a sense of that diversity. The photos are all of different species photographed by yours truly off NE Vancouver Island.

Yet, even major news outlets have reported on sea stars as if they are all ONE species (includes CBS and Phys.org).

 

 

Why does this matter?

Not only do different species of sea star have different ecological niches, but communication about them as if they are one species has greatly confounded the understanding of what is happening with Sea Star Wasting Disease (SSWD). When a few individuals of one species are seen, this has been extrapolated to text like “But now, the species is rebounding.”

Which species? Where? Did the individuals survive?

This sort of “collective” perception is also often reflected in comments on my social media posts. When I post about any sea star species, comments like the following often result: “Good to see “THE sea stars” are coming back.”

Yes, some species appear to be doing better since the onslaught of SSWD beginning in 2013 e.g. Ochre Stars. Other species do not appear to have been impacted much at all e.g. Blood Stars. But the world’s biggest species – the Sunflower Stars who help maintain kelp forests – are now recognized as Critically Endangered by the International Union for Conservation of Nature (see further information below).

The odds are already stacked against the appropriate learning about the conditions causing SSWD because it is happening in the dark, below the surface.

Blurring this group of extraordinary starred animals into all being the same, risks an even greater loss of understanding, colour, diversity . . . and action. 💙

 

---

Further content about the IUCN designation from my post on social media:

 

It’s official and so important to know. The iconic, world’s largest sea star species, the Sunflower Star, has now been added to the International Union for Conservation of Nature (IUCN) list as Critically Endangered.

This is no surprise to those of us who have been monitoring their health but to many, Sea Star Wasting Disease is unknown, even though it is one of the biggest known wildlife die offs in recorded history.

It has happened largely out of sight, beneath the Ocean’s surface. Further, there are many of us who do not have enough understanding / appreciation of (1) the connection between land and sea and; (2) the different sea star species and their ecological importance. Seeing sea stars of other species does not mean that all species are okay. Sunflower Stars (Pycnopodia helianthoides) definitely are not.

It is positive that they have been officially “listed”. With this recognition of how at risk they are, there is better potential for resources and action to find out what has caused the die off and what this might be indicating about changing environmental conditions. There is the hope that more people will care.

This is an international designation. The species also needs to be assessed in Canada to determine “status” and potential protection / action under the federal Species at Risk Act.

The December 10th Nature Conservancy media release includes:

“Populations . . . experienced dramatic crashes in response to a marine wildlife epidemic event – referred to as sea star wasting syndrome – that began in 2013. Using over 61,000 surveys from 31 datasets, The Nature Conservancy and expert ecologists at Oregon State University calculated a 90.6% decline in the global population of sunflower sea stars due to the outbreak and estimated that as many as 5.75 billion animals died from the disease . . . “The rapid decline of this giant sea star, and of the sea kelp forests that it helps preserve, highlights the importance of every single species on the IUCN Red List of Threatened SpeciesTM. Its entry into the IUCN Red List in the highest threatened category emphasizes the need for urgent action to understand and combat the wasting disease that is sweeping through the population. We hope that this listing leads to positive action and recovery for this species and its ecosystem,” said Caroline Pollock, Programme Officer for the IUCN Red List Unit. Sunflower sea stars are now nearly absent in the contiguous United States and Mexico. No stars have been observed in Mexico since 2016, none in California since 2018, and only a handful in the outer coasts of Oregon and Washington since 2018. They are still present in Puget Sound, British Columbia, and Alaska, but only at a fraction of their former population in most places.”

Above video by the Hakai Institute.

---

See the full December 10th media release at: “Iconic Sea Star Listed Critically Endangered After Study Finds Marine Epidemic Event Nearly Wiped Out Global Population”

I’ve maintained a record of the research related to Sea Star Wasting Disease at this link.

Another related blog showing the diversity in just one species is “Rose Star – No Two Alike”.

An excellent resource to ID local sea stars is Neil McDaniel’s website at this link.