Wednesday, May 13, 2009

Sea Star Die-off in North Kingstown

Yesterday, I responded to a call from a North Kingstown resident who reported thousands of dead and dying sea stars (or starfish) washing up on the shore of Wild Goose Point.

Save The Bay's Director of Communications John Martin and I headed down there with a video camera and shot this youtube video:



This is a natural phenomena that we see every few years at this season when the sea stars move into the shallows to feed on newly-set barnacles and other shellfish. As I explain in the video, we believe it was caused by a layer of freshwater floating down the Bay after days of heavy rain, which the saltwater-dependent stars can't tolerate.

I should have pointed out that everything else down there was in order- steamer clams were squirting, striped bass were schooling, snails were ooching, and crabs were scuttling around. There was no chemical odor or sheen and no obvious pollution of any kind.

Sea stars can be a nuisance, as they eat quahogs and other valuable shellfish, but they do play in important role in the Bay ecosystem, so it's worth investigating any time there are reports of unusual occurences like this.

There's no special call to action attached to our message here, but it does underscore the need to support environmmental monitoring in the Bay so we can keep track of events like this. As the strong media response to our video proves, people are interested in these things and they care about the health of animals of the Bay. Thanks for tuning in! JT

5 comments:

  1. John

    I saw the clip on starfish kill in NK. Do you have any YSI data to indicate salinity was really low in the open area they were in ? They normally hang out at a meter depth or more, and it seems unlikely the FW would impact anything but those right on the intertidal zone. I've seen articles on coral reef die offs following sudden pop explosions due to overpredation that starves out the pop. I would suspect this is like other starfish kills in previous years (usually in the Fall). No one has been able to explain them fully , but it is thought that lack of adequate food and disease play a role as large pops fluctuate wildly. Unfortunately, no one seems to be watching such "unusual" events - might be a good thing to track such events over the long term.

    Chris



    Christopher Deacutis, PhD
    Chief Scientist
    Narragansett Bay Estuary Program

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  2. Chris, you make good points as always. I did not test salinity at this site, but we've done some tests recently in nearby areas of the Bay and observed stratification and very fresh water on top. Also, I observed bloated and burst sea-stars which goes to the fresh-water hypothesis. However, you may be right that it's a natural boom and bust of sea stars. That's why we need to do better monitoring and keep track of stuff like this! Thanks for your comments and all the great work you do. JT

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  3. A quick update on this- The last round of northeast wind deposited yet another pile of sea stars at northeast facing locations in North Kingstown. This time, the northeaster was not accompanied by heavy rain, so I am leaning more toward Dr. Deacutis' hypothesis (above) of boom and bust than fresh water kill. I should point out that Dr. Vin Rose, a URI professor and Save The Bay board member also weighed in to let me know that sea star booms and die-offs used to be much more common in the bay decades ago when we had a strong scallop fishery. -JT

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  4. Barbara Walton-Faria4:41 PM

    I have noticed a similar sea star die off on Prudence Island at Sandy Point over the past couple of summers. It usually occurs in August - I haven't noticed whether or not it corresponds to recent rain events - but I will keep that in mind next summer.

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  5. Anonymous7:15 PM

    We in South Carolina noticed a sea star die-off in late December 2009. Not really associated with any fresh water issues that I'm aware of; not seemingly associated with any unusual temperature changes. Would love to help take data if someone is interested in researching this issue.

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