Thursday, November 29, 2012

November 26, 2012 Ocean Sunfish Stranding in Kingston, MA

Dead Ocean Sunfish at Rocky Nook, Kingston MA

Ocean sunfish carcass finally exposed at the water's edge. 
View of ocean sunfish carcass looking back towards the beach. 
This morning, Nancy Borsari called to report a dead ocean sunfish in Kingston, MA. Most strandings of ocean sunfish occur on Cape Cod so this was an usual sighting for us.  With a quick call, Leah was at my house and ready to head out to Kingston to find and necropsy this carcass.

Leah taking photos of carcass. 
Since NECWA is a volunteer non-profit, Leah was helping out on her own time. Leah recently graduated from Bridgewater State University in Biology and has been with NECWA for many years. NECWA is grateful for her help and the help of the other biologists and professionals within the community that volunteer their time and expertise on behalf of these amazing animals. Thanks Leah!

Head-on view of this ocean sunfish. 
In an effort to help us locate this carcass, Nancy met us down at Rocky Nook and directed us to where she had seen the carcass the day before. Tides and currents can quickly move a carcass from one location to another, so having someone with first-hand information on the beach is very helpful.

Leah standing on rocks to get a more complete photograph of the carcass. 
We found the carcass, but it was covered by a foot of water. The tide was ebbing so we decided to all meet back at Rocky Nook later that morning. When we returned, the carcass was completely exposed on the beach and this allowed us to finally start our external examinations.

The first order of business was to collect as many photographs of the carcass as possible. Then we set-up our portable weighing tripod and weighed this carcass which came close to 300 lbs. With Nancy's help, we collected a number of body measurements and then sampled tissues for later DNA analysis.

Nancy recording the weight of the carcass on our data sheet. 
Portable tripod in action!
Our final activity was to open up the carcass to determine the sex of this ocean sunfish. This turned out to be a male fish as Leah quickly found the testes close to the vent. Ocean sunfish are a bit different than most fish for they only have one gonad or sex organ. 

Cut from the vent up to expose the gonads. 
Testes extracted so we can measure and weigh. 
As dusk was approaching, we had to pick up the pace a bit. We did examine the entire digestive tract, from stomach to large intestine and measured its length at close to 17 feet!  When we were done, we were tired and wet and smelly as ocean sunfish have a very strong smell, especially ones that are decomposing. 

Entire digestive tract - close to 17 feet in length. 
A big thank you to Nancy and her mom Ann for helping us locate and necropsy this carcass. One of the benefits to our work is meeting incredible people like Nancy and Ann and having their support for the work we do in the New England area. NECWA is a team effort and we appreciate all the help from members of the community! Thanks again Nancy and Ann!