NOAA Teacher at Sea
Methea Sapp-Cassanego
Onboard NOAA Ship Delaware II
July 19 – August 8, 2007
Mission: Marine Mammal Survey
Geographical Area: New England
Date: August 3, 2007
Weather Data from Bridge
Visibility: 5 in haze lowering 3 to 5 in showers
Wind Direction: Southwest
Wind Speed: 10-15 knt increasing to 20 knt.
Swell height: 3-5 feet building 4-6 feet
Science and Technology Log
Today was another great day for sightings. Critter counts include sperm whales, white sided dolphins, a whopping 17 minke whales, a Sei whale, offshore bottle nose dolphins, a finback whale, another pod of pilot whales and 100’s of common dolphins. At one point during my starboard observation shift, both I and my portside counterpart were calling off sightings so rapidly that the recorder was having problems keeping up with us. We both paused for a moment and pulled away from the big eyes to look around and discover that we were surrounded by literally 100’s upon 100’s of common dolphins. The sea was frothing with their activities; some doing aerobatics, others charging, some came to bow-ride of the ship, while other could be seen chasing large fish which were identified as yellow-fin tuna.
In a repeat from several days ago the pilot whale sighting prompted another launch of the zodiac…only this time I got to climb down the Jacob’s ladder and go for a zodiac ride which brought me as close to pilot whale as I could ever hope to be. We were able to procure 5 tissue samples for further genetic study along with an untold number of dorsal fin photographs. (Please see log from August 1st for further explanation of these genetic studies and photos.) My job on the zodiac was to fill out the photography data sheets which record the GPS headings, frame numbers, animal position within pod, approximate size of animal, special markings on the animal, if an attempt to biopsy the whale was made, if the shot resulted in a hit or miss….etc. I was madly recording all this information as cameras were shooting and crossbows were firing and the whole experience whizzed past me. I hope I didn’t forget to record anything!
Aside from all the sightings (some of which have become rather common place), and my zodiac ride I really have nothing left to report for the day….except of course that the day flew by. In fact every day passes in a blink…even the foggy ones. I suppose that’s what happens when each day is filled with something new to see and do. Before I sign off for the day I’ll leave you with two more species profiles. One of which may surprise you!
Yellow warbler (Dendroica petechia)
There are approximately 40 subspecies of this widely distributed little bird. This bird, in particular, was most likely from the subspecies aestiva thus making it a ‘Northern’ yellow warbler.
As a true bird-lover I’ve been taking notice and taking note of every new bird I’ve seen while out at sea, and naturally all of the birds I’ve seen lately from black-backed gulls to shearwaters are suppose to be out here in the open ocean searching for fish and bobbing around in the waves while resting. The yellow warbler however is not suppose to be here….and in fact being at sea means certain death for the delicate songbird as its food source is almost non-existent out here and it is ill-equipped to handle a lack of freshwater. The warbler pictured above probably hitched a ride with us following our 24 hour port call in Yarmouth, Nova Scotia. Sad to say that this warbler did in fact perish at sea despite my offerings of fresh water and bread crumbs (I was all out of their primary food which are insects!) A second warbler and a grosbeak did however find the boat as we were coming back into harbor so we hope they were more fortunate then the first stowaway.
Identification: The yellow warbler is fairly large compared to other warblers and has an exceedingly short set of tail feathers. Both sexes have a yellowish green head and back with yellow underbellies. Females tend to be a bit duller in color while males typically have brown streaks on the cheek and breast. Distribution: The Northern Warbler breeds from Alaska to Newfoundland and Southern Labrador, south to South Carolina and into Northern Georgia, and as far west as the Pacific Coast. It is also found periodically in the American Southwest. Migration: Winters in the Bahamas, Northern Mexico, Peru and the Brazilian Amazon. Diet and Habitat: In its northern and eastern distribution the warblers live in damp habitats surrounding swamps, bogs, marshes, ponds and stream or river banks. They will also feed and nest in woodland areas, meadows, and overgrown pasture lands. In the west and southwest the bird is restricted mainly to riparian habitats. Unfortunately riparian habitat is rapidly decreasing in the Southwest as are the population of yellow warblers within this region. The warbler feeds primarily on insects, but will occasionally eat berries. Listen to its song here.
Common Dolphin
Until recently both the short-beaked and long-beaked common dolphins were considered to be one species. Although much of the recent research and literature still does not differentiate between short-beaked and long-beaked, they are technically two different species. For the purposes of our survey we also did not distinguish between the two as they are nearly identical in physical appearance.
Short Beaked Common Dolphin and Long-beaked Common Dolphin
Identification: Very distinctive crisscross patterning on the sides; yellow/tan patches on the side, dark gray over the topside and pale underside. Light grey patch along the peduncle of the tail.
Max length and weight: 330 pounds and 9 feet. Males are just slightly larger then females
Diet and Feeding: Fish and squid
Migration: No organized or seasonal migration
Distribution: Widely distributed throughout the Atlantic, Pacific, and Indian Oceans as well as the Black and Mediterranean Seas. Special Note: Common Dolphins are especially active and are commonly seen doing aerobatics and bow riding. They are also extremely vocal; to such a degree that their high pitched whistles and clicks may be heard above water.
References
Collins Wild Guide: Whales and Dolphins. Harper Collins Publishers, New York, New York, 2006.
