Surveying for Marine Mammals, Turtles and More

Report from the AMAPPS Bigelow survey on 6July2016, our first bad weather day.

The 2016 AMAPPS (Atlantic Marine Assessment Program for Protected Species) marine mammal and sea turtle abundance survey started on 27 July 2016. This is a multi-platform survey involves two ships (the NOAA ships Henry B. Bigelow and Gordon Gunter) and two NOAA Twin Otter airplanes that will together survey waters along the entire US Atlantic coast from Maine to Florida and from the shore line to the 200 nautical mile US exclusive economic zone (EEZ) during 27 July – 28 Sept 2016. These surveys are being led by the Northeast and Southeast Fisheries Science Centers and funded by the Bureau of Ocean Energy Management (BOEM), the National Marine Fisheries Service (NMFS, also known as NOAA Fisheries), the US Navy and the US Fish and Wildlife Service (USFWS). In addition, our Canadian colleagues are conducting an extensive aerial survey using two planes during the same time period covering Canadian waters around Nova Scotia and Newfoundland . One other large scale cetacean abundance survey, known as SCANS (Small Cetaceans in European Atlantic waters and the North Sea) III  is also taking place this summer around Europe.

There are 2 teams of visual observers on the AMAPPS Bigelow shipboard surveys that are scanning the waters using high powered binoculars looking for whales, dolphins, turtles, and seals and using line transect sampling methods. During 28 Jun – 4 Jul 2016 we covered about 575 nautical miles of track lines off the coasts of Virginia and Delaware and have already seen more than 2000 animals from 15 species. So far the most common species are common dolphins and striped dolphins. We have been in warm Gulf Stream waters where we have seen spinner dolphins (below).

spinner_dolphin

In the deeper waters we have already seen three species of beaked whales (see below for more on these species). One of the most spectacular sightings we had was a group of about 24 false killer whales feasting on a large fish.

amapps_false_killer_whales.jpgPhotos of spinner dolphin and false killer whales by Richard Holt under MMPS permit number 17355-01.

In addition to searching for marine mammals there is a team of observers dedicated to searching for birds. The seabird team, conducting a modified 300 meter strip transect, found 390 birds representing 19 species, so far. We averaged about seven species per day, the exception being 4 July on line 25 when we found a remarkable 12 species including our first White-faced Storm-Petrel and South Polar Skua of the cruise. Furthermore, 961 seabirds were counted in six multi-species feeding flocks, consisting almost entirely of the three expected shearwater species: Cory’s, Great, and Audubon’s Shearwaters. These feeding flocks were almost all farther offshore in  warmer water, presumably associating with feeding tuna or other predatory fish. Highlights, and there always are highlights of one sort or another, were three Trindade (aka Trinidade) Petrels, a single Black-capped Petrel (all about 170 to 190 nautical miles east of Cape Charles/Cape Henry) and a confiding immature Brown Booby (below) wandering somewhat farther north than expected. The seabird team remains on a high level of alert as we survey the outer lines, eager for what other warm water species we might find out here. We collectively cry “East!” and the farther east (or southeast), the better. It’s all about the Gulf Stream, isn’t it?

brown_booby_bigelow_amappsBrown Booby that used the Bigelow as a resting spot. Photo by Michael Force

There is also a team of scientists listening for animals using hydrophones that trail behind the ship. We’ve had a  air diversity of species during this first week of the AMAPPS cruise. Sperm whales seem to be heard almost everywhere, and we’ve had some of their other click types besides the usual (ie: creaks and codas). We had a really good day where the visual team was able to spot and bring us to various different groups of dolphins and give us the opportunity to collect really high quality unambiguous recordings. We also managed in one week to collect recordings on the three species of beaked whales that we’ve encountered in the past (Cuvier’s, Gervais’, and Sowerby’s). The sonobuoys are being deployed every night to listen for the presence of baleen whales (which the array cannot detect). So far we have not heard baleen whales, but have detected sperm whales and dolphins.

Lastly, to learn more about the ecosystem that these marine mammals and turtles are living in we have scientists collecting data on oceanography and plankton. These scientists work at night utilizing a range of instruments, imaging systems, and nets. For oceanographic properties of the water like temperature, salinity and density, a CTD (Conductivity, Temperature, Depth) is lowered through the water column. The EK60 is an active acoustic instrument on the hull of the ship that pings in 5 different frequencies to detect animals in the water column ranging in size from 1cm plankton to adult fish. Phytoplankton, individual celled plants less than 0.5mm in size, are being imaged from the surface water by an Imaging FlowCytobot. The zooplankton, animals 5mm to 2cm in size that live in the water column, are being imaged by a towed Video Plankton Recorder. Zooplankton is also being sampled using two net systems: a 61cm bongo, which is a standard plankton net, and a 2m x 1m neuston modified with weights to sample from the surface to 25m depth. The samples collected with the nets will have all the zooplankton and larval fish in them identified back at the lab, but we will especially be looking for bluefin tuna larvae, which were not previously thought be in the study area. Out here in the Gulf Stream, salps, a gelatinous type of zooplankton, have been the most frequently seen species in the nets. In fact each net may have over a gallon of salps that must be sieved out and discarded before the sample is preserved.

salp_amapps_bigelow

Above: Images of the most common salp, Salpa aspera, in its chain form and solitary form taken by the Video Plankton Recorder, and an image of a layer of salps around 50m depth as seen by the 200kHz transducer of the EK60.

The AMAPPS Bigelow Team, Leg I

 

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