Thursday, March 29, 2012

Bita Bay House, Green Turtle Cay, Bahamas

NECWA Member Kari Heistad visits Green Turtle Cay, Bahamas

Kari Heistad recently returned from a trip to tiny island of Green Turtle Cay, Bahamas. She shared some thoughts with NECWA News.

Can you tell us a little bit about the island?

The island is located just off from the island of Abaco, about 115 miles east of Ft. Lauderdale, Florida. You get to the island by flying into Treasure Cay on Abaco and then taking a 15 minute ferry ride to the island. Green Turtle Cay is only 3 miles long and 1/2 mile wide, so you are never out of sight of the ocean when you are on the island. The island was settled by people from New England so the architecture of the homes more closely resembles New England than typical Caribbean homes. In fact, the town on the island is called New Plymouth. There are only 500 people who live on the island so it is a close knit community.

What drives the economy of the island?

The island has long been the playground of boat owners who wanted a place to enjoy beaches and few tourists. The entire island has great beaches and snorkeling and a laid back atmosphere so that even though stars such as Leonardo di Caprio go there (he was there just before we were) none of the locals treat them any different. So, tourism is a large part of the economy. The other part of the economy is fishing.

While tourists can catch the Caribbean spiny lobster (different than the lobsters of New England with no front claws and a larger tail and a different taste to the meat) while snorkeling, only Bahamians can fish for lobster commercially. They do this by using air hoses up to 100 feet long that allows them to fish for lobster for longer than if they had to come up for air frequently. Islanders also fish for grouper and other fish. All of this is exported off the island.

Blue Tangs taken while diving with Treasure Divers

Are there any maritime issues?

The island is a place where green turtles live and so there is always a concern about protecting them and their nesting areas. One large and recent issue for the island as well as the rest of the Caribbean is the massive infestation of Lion fish. These are fish that are native to the Pacific ocean and so they have no natural predators. They are taking over entire reefs, eating small fish and the coral and creating devastation. The Bahamian government is seeking ways to eliminate it as quickly as possible.

Green Turtle Cay has teamed up with REEF to offer a fishing derby where teams compete each summer to see who can catch the most Lion fish in a day. Last year the derby took 1300 fish out of the water. Chefs from Florida came over and showed people how to cook the fish and make them into a taste treat. My brother Per borrowed a spear gun and managed to kill 20 while we were snorkeling during the week.

What did you enjoy most?

The people are just terrific for one thing. We found people to be very open and friendly and happy to talk to us. We spent several evenings in the Sundowners bar where locals gather to play pool and games of Connect Four. Just hanging out gave us a chance to meet people and learn about island life. The other part that we enjoyed was the great snorkeling. The water just off the beaches is fairly shallow and yet we were able to see schools of Houndfish, an 18 inch Filefish and many of the tropical fish local to the Caribbean.


When is the best time to go?

High season is May - July on the island, but August and into the fall is a great time to go. The water is still warm from the summer and there are few people there. Some of the resorts run specials in October to boost occupancy. Many people skip the fall due to the fear of hurricanes but as was pointed out to me, there is only a 3% chance that you will have a hurricane, so there is a 97% chance you will get a great vacation.

Would you recommend the island for tourists?

I would strongly recommend the island to people looking an adventure vacation. There is only one small gift shop on the island so you don't go there for shopping. But, if you are looking for the kind of vacation where you are in the middle of daily life and you like a sense of adventure, this is a great place. You can rent houses by the week right on the beach or stay in one of the more upscale resort complexes. Everyone gets around on golf carts and getting over some of the limestone roads is a bit like four wheeling in a jeep. If you want to get away from it all and have great beaches, snorkeling, diving and wonderful people, this is the island for you.

Sunset over New Plymouth, Green Turtle Cay, Bahamas

Tuesday, March 6, 2012

Sea Turtle Necropsies in 2012

Sea Turtle Necropsies in 2012

Each spring NECWA assists Bob Prescott, Director at the Wellfleet Bay Wildlife Sanctuary, and his staff with necropsies (animal autopsies) of cold-stunned sea turtles. These are juvenile sea turtles that had washed ashore dead on the northern shores of Cape Cod.

Every weekend in February, NECWA staff and interns assisted with these necropsies that are conducted in a state-of-the art necropsy facility at the Marine Mammal Center at Woods Hole Oceanographic Institution. Last year, Wellfleet Bay and NECWA spent 3 weekends necropsying over 200 sea turtles that had stranded over the course of a few years. This season, there were fewer sea turtles to necropsy since we had caught up on the backlog created from previous years of strandings.

This past Thursday, Krill was able to bring 3 carcasses to Bridgewater State University so students in Dr. Jahoda's Comparative Anatomy Class could examine them in more detail. This was a great opportunity for Dr. Jahodah's students for it allowed the students to see what is involved in a sea turtle necropsy and how the data is collected. A few of Dr. Jahoda's students are continuing with this work and will be preserving the skeletons for BSU as part of a group project.

So why do these young sea turtles strand each fall and early winter on Cape Cod Beaches? Both juvenile loggerheads and Ridley's normally migrate into our Cape Cod waters to feed over the course of the spring, summer and fall. As fall approaches and water temperatures drop, animals begin to migrate back south into warmer waters for the winter. Unfortunately, some sea turtles get trapped by the arm of Cape Cod for it acts as a physical barrier to their movement south. As water temperatures continue to drop, these turtles become cold-stunned as their body temperature decreases to dangerously low levels. No longer able to swim or function normally, many cold-stunned individuals wash up on the beaches of Cape Cod that border Cape Cod Bay.

For over 25 years, MA Audubon at Wellfleet Bay has maintained a sea turtle rescue team comprised of staff and trained public volunteers. Members of this team walk the beaches of Cape Cod looking for cold-stunned sea turtles that have washed ashore. When sea turtles are found, dead animals are collected and frozen for later analysis and live turtles are stabilized at Wellflleet Bay before being transported to the New England Aquarium for treatment and rehabilitation.

Over the past few years, NECWA has been able to include many BSU students in these necrospy events. Last year, 5 BSU students assisted with necropsies including Leah Horeanopoulos, Meghan Donovan, Lauren Babb, Tara Frare and Chelsea Hedderig. This year, Meghan, Tara and Lauren all returned to help necropsy sea turtles down at WHOI as well as 4 of Dr. Jahoda's Comparative Anatomy students that we had just worked with Krill and Dr. Jahoda that Thursday.

Much thanks to Bob Prescott and his team for allowing NECWA to become involved in these necrospy events. These events are great opportunities were students and staff get a chance to meet and work closely with professionals in the field of marine science. And our efforts are helping scientists like Bob Prescott and others to better understand the biology and ecology of these amazing animals.

To read an article in the BSU Newslog, click on the image below.

Friday, March 2, 2012

Donation of South Bay Technology Saw for Ocean Sunfish Aging Research

Donation of Low Speed Wheel Saw for Ocean Sunfish Aging Research

NECWA would like to thank Mark E. Goodrich, President of E. McGrath Inc., for the very generous donation of a used Low Speed Wheel Saw. NECWA was in great need of this precision saw for our ocean sunfish aging research. This saw will be used to cut the vertebrae collected from dead ocean sunfish that wash ashore on our Cape Cod beaches each fall. It is hoped that once the vertebra are cut, the bands on the centrum surface can be used to determine the age of this very large and unusual looking fish.

Photo courtesy of Greg Skomal

Krill and her son Jamie went to meet Mark at E. McGrath Inc. in Salem and pick up the donated saw. Mark showed them around the buildings and discussed proper operation of the saw and possible blades that would be appropriate for cutting the bones of ocean sunfish. This donation is very important to the research that NECWA is attempting and we are sharing our results with other researchers in the United States and abroad.

Ocean sunfish migrate north each spring to feed in the cold waters of the Gulf of Maine. We typically start seeing young ocean sunfish move into our coastal waters in August as they move closer to shore to feed on jellyfish, ctenophores and other gelatinous critters. As fall approaches and water temperatures drop, the majority of ocean sunfish start migrating south to warmer, more tropical waters.

However, some individuals get caught in the arm of Cape Cod and become trapped by the physical features of the Cape itself. These unfortunate individuals are unable to continue their journey south and get stuck in our harbors and bay areas. As water temperatures continue to drop, these animals become cold-stunned and wash ashore on Cape beaches.

NECWA maintains a stranding response team that tries to rescue live animals that are coming ashore. If the animals wash ashore dead, then we perform a necropsy (animal autopsy) on the carcass and collect tissue samples for further analysis.

NECWA staff members Krill, Tammy, and Belinda have been working on an aging study for ocean sunfish. This research has been conducted in conjunction with Tracey Alleyne-Greene who is a student at Bridgewater State University and is working under Dr. John Jahoda.

Unlike other bony fish, ocean sunfish lack well-developed otoliths or "fish ear bones." These structures are consist of three pairs of small carbonate bodies found in the head of bony fish and function in hearing and gravity perception. These abilities are very important to any fish that moves throughout a three-dimensional water column. The image below shows one pair of otoliths that were collected from a cod.

Otoliths are typically used by fisheries biologists for aging purposes. Not only do ocean sunfish lack developed otoliths, but the skeleton of those animals that wash ashore on our Cape beaches each fall is reduced in complexity and is comprised of a porous bony material. Perhaps this is because the ocean sunfish in our area are young animals (as determined by size only) and therefore, their bones have not fully developed.

The images below show the entire otolith of an ocean sunfish. The second image is a close-up of the first image.

The image below shows a sectioned otolith that has been magnified and photographed.

Since we were not able to use otoliths to age ocean sunfish, the NECWA team decided to try an aging technique used by fisheries biologists who study cartilaginous fish, such as sharks, skates are rays. This aging technique involves examining and often sectioning the vertebrae to examine the banding pattern in the centrum or center face of the structure. It is assumed that each band pair, made-up of a light band/dark band combination, represents one year of growth for the individual.

We are still trying to work out a suitable protocol that will allow us age ocean sunfish using this vertebral banding pattern. And at present, we are not confident that this method will work for this pelagic species that seems to migrate to stay within a narrow temperature range. These types of ups and downs, curves and dead-ends, are all part of science and the scientific process of discovery. Although it can be frustrating at times, we are committed to this research and are loving the adventure.