June 15, 2010

June 15, 2010

Aboard: R/V Hugh R. Sharp

Weather Data at 1:30pm EDT: Clear and sunny, 14.5˚C

Location at 1:30pm EDT: Lat: 41 23.78 N Long: 66 56.64 W

Water Depth: 68.2 m

8^th Day at Sea

What kinds of things are you going to catch? Part 2 – non-fish along with a few new fishes

There are many more species in the areas than I have listed here; these are simply the ones that I found most interesting. There are several different types of bivalves, sea weeds, etc. Material about the species on this page came from several sources, including the Bigelow and Schroeder’s book referenced in the previous posting. Also, Kenneth Gosner’s A Field Guide to the Atlantic Seashore published by Houghton Mifflin Company in Boston, Ma, 1978. I also used Norman Mein-Koth’s Field Guide to North American Seashore Creatures published by Alfred A. Knopf in New York in 1990.

Sea Stars (aka starfish) – Every third dredge, the contents of the dredge are sampled and the sea stars are separated by species and counted. Most sea stars can regenerate a lost arm, but a few can regenerate an entire organism from the lost arm as well. All sea stars are predators; many species do eat scallops.

Hippasteria phygiana – a cushion star with a much wider central disk and shorter arms than the other types of sea stars.

Northern Sea Star (Asterias vulgaris) – is one of the more common sea stars found. It can have a radius of up to 20 cm.

Blood Star (Henricia sanguinolenta) – is a thin armed sea star that ranges in color from bright red to orange. This particular blood star shows some aberant regeneration occurring on one arm.

Leptasterias tenera - smaller sea stars than the others. They are usually whitish-tan. Some have purple centers and arm bands.

Sclerasteras tanneri - are spinier than the other sea stars seen. They are bright red with thin arms.

Spiny Sun star (Crossaster papposus) – is the only sea star that I’ve seen here with more than 5 arms. It has concentric rings of color radiating from the central disk of the sea star.

Green Sea Urchin (Strongylocentrotus droebachiensis) – can grow up to 8.3 cm wide and 3.8 cm high. The shell (test) is usually a greenish color and the spines are all approximately the same length.

Sand Dollar (Echinarachnius parma) – the common sand dollar. This species does not have openings in the test like the Keyhole type that is commonly found off the coast of the Carolina’s, but does have the flower-like markings on the dorsal side. A great many of these (hundreds of thousands) are found in the dredge on some tows.

Hermit Crabs (various species) – move from shell to shell as they grow.

Northern Lobster (Homarus americanus) – can grow up to 90 cm in length. Lobsters are scavengers and can be cannibalistic. Claws and tail are highly prized for meat.

Winter flounder (Pseudopleuronectes americanus) – are darker than the other flounder. Like summer flounder, they can change color to match the underlying ocean floor. Winter flounder can live up to 15 years. They can reach a maximum size of 64 cm and 3.6 kg, with the average being 31-38 cm and 0.7-0.9 kg. Winter flounder eat mostly small invertebrates, like polychaetes and shrimp and some small fishes. They are preyed upon by cod, skates, goosefish, and spiny dogfish. Winter flounder are the thickest of the flatfish, but are considered over-exploited.

Haddock (Melanogrammus aeglefinus) – a silvery fish that is dark grey on the dorsal side with a dark patch behind the gills. The largest recorded haddock was 111.8 cm long and 16.8 kg. The average haddock is 35-58 cm long and 0.5-2 kg. Small haddock eat crustaceans, polychaetes, and small fish, while larger haddock eat more echinoderms, but will eat most anything. Predators include spiny dogfish, skates, cod, other haddock, hakes, goosefish, and seals. Haddock aquaculture was begun in 1995. The biomass of haddock was considered below maintenance levels in the late 1990s.

Fawn Cusk-eel (Lepophidium profundorum) – are greenish with light green or tan spots down the sides and, unlike true eels, have pectoral fins. They average about 26 cm in length. They eat sea mice, shrimp, and echinoderms. Larger fawn cusk-eels eat flatfish as well. They are eaten by skates, spiny dogfish, hakes, flounders, and sea ravens.

Winter Skate (Leucoraja ocellata) – large, heart-shaped skate. Like the barndoor skate, winter skates can be quite large, up to 150 cm long. They eat bivalves, shrimp, crabs, echinoderms, and many types of fishes. They are eaten by sharks, other skates, and grey seals. They are considered to be commercially important.

Personal Log

I have to admit, when I first went up to the bridge of the ship, with its wrap-around windows, the first words that came to mind were the lines from Rhyme of the Ancient Mariner (which I may have not remembered entirely correctly)

Water, water everywhere

And not a drop to drink
Water, water everywhere
And all the boards did shrink

At the time that I was there, no land and no other ships were within sight; there was nothing but water and wavelets as far as I could see. We’ve see several ships on the horizon, and two container ships close enough to get a good look at. One of those passed quite close as we had a dredge down.

June13 2010

June 13, 2010

Aboard: R/V Hugh R. Sharp
Weather Data at 1:30pm EDT: Pouring, 13.7˚C
Location at 1:30pm EDT: Lat: 40 43.37 N Long: 67 53.12 W

Water Depth: 69.6 m

6^th Day at Sea

What kinds of things are you going to catch? What lives with the scallops? These questions were also quite common before I boarded the Hugh R. Sharp. I’d like to introduce you to some of the species that are included in the dredge with the scallops (or sometimes, instead of the scallops). All of these are termed “bycatch” and are counted and/or measured and then thrown back. As before, pictures of most of the species will be added when I am back on land. In this log, I will talk about the fishes that are often in the dredge. Most of this information came from Bigelow and Schroeder’s Fishes of the Gulf of Maine, edited by Collette and Klein-MacPhee, 3^rd Edition (2002).

Flounder – Flounder are a flat fish with both eyes on the same side of the fish when they are adult. As young, they eyes are on both sides, as in most fish, but as they mature, one eye migrates to the opposite side and the fish lays flat. In general, they are a mottled brown to blend in with the ocean bottom.

Fourspot Flounder (Paralichthys oblongus) – have four distinct spots on the dorsal side: 2 near the tail and 2 in the middle, above and below the lateral line. They eat cephalopods (squid and octopus), crustaceans, and other fish. Predators include spiny dogfish, goosefish (see below), silver hake (see below), and other flounder.

Windowpane Flounder (Scopthalmus aquosus) – more round than other flounder. They can reach a maximum size of 51cm and weigh more than 1 kg, but average between 25-30 cm in length. They eat decapods (shrimp) and other fishes. Predators include sharks, skates (see below), cod, and dogfish. Windowpane flounder are not considered commercially important, but have been used as an indicator species in Long Island Sound.

Summer Flounder (Paralichthys dentatus) – have highly variable color patterns that they can actually alter for camouflage. They don’t replicate the ocean floor underneath, but change their patterning to blend in with the substrate. Males can reach 61cm and 2.6 kg while females can reach 94 cm and 13.4 kg. They average 40-56 cm and 1-2.3 kg with females generally being larger and heavier for their age than males. Summer flounder eat other fishes (including other flounder), cephalopods, and crustaceans. Predators include sharks, skates, cod, goosefish, silver hake, etc. Commercially, summer flounder are one of the most important flat fish in the north Atlantic. Commercial aquaculture of summer flounder began in 1996.

Yellowtail Flounder (Limanda ferruginea) – more evenly pigmented than other flounders and have yellow streaks on the ventral edges near the tail. Males reach an average size of 40 cm and females reach 46 cm. They eat cnidarians, crabs, bivalve mollusks, echinoderms, and other flounder. Their predators include spiny dogfish, skates, goosefish, hakes, halibut, and four spot flounder. Yellowtail founder are one of the most commercially import flat fish in the area. By the late 1990s, they were considered to be fully exploited and rebuilding local stocks.

Goosefish or Monk fish (Lophius americanus) – is a type of angler fish. Angler fish use a lure to attract prey fish nearer the mouth of the predator. Goosefish have a mouth that is enormous for the size of the fish and which opens upward. The teeth are plentiful and all point back into the mouth so that in trying to escape, the prey simply impales itself more tightly onto the teeth. It also has spines on the dorsal side of the head. There are confirmed incidences of goosefish eating diving birds, but stories of them eating geese are probably apocryphal. Goosefish can reach 120 cm in length and 27 kg in weight. They eat bony fishes, cephalopods, elasmobranchs, and occasionally birds. Not much eats goosefish, though smaller ones are eaten by larger goosefish, sharks, and swordfish. . There is a commercial market for monkfish, Julia Childs is often credited with making it popular with a recipe she did on one of her shows.

Red Hake (Urophycis chuss) – are silvery fish with a reddish tint on the head, very similar to the picture below. They can grow to 50 cm and 2 kg with the females being generally larger than the males. They eat decapods, polychaetes (sea mice), crustaceans, and other fishes. Their predators include dogfish, cod, goosefish, and silver hake. Commercially, they are used in animal feed and larger ones are used for human consumption. They are considered underexploited.

Silver Hake (Merluccius blinearis) – are silvery fish that are generally a darker grey than the red hake. They can be larger than the red hake, up to 76 cm and 2.3 kg. They eat other silver hake, crustaceans, and other fishes. Many other fishes as well as harbor porpoises consider the silver hake to be prey. Commercially, they are used as fresh fish, canned pet food, fertilizer, and fish meal. They are unsuited to freezing. Silver hake are considered fully exploited.

Little Skate (Leucoraja erinacea) – are trapezoidal, purplish brown and spotted on the dorsal side. They also have thorns present on the dorsal side. Little skate females release a single, fertilized egg in a distinctively shaped egg case. They reach a maximum length of 54 cm and eat fish and invertebrates, including gastropods, bivalve mollusks, crabs, etc. They are eaten by sharks, other skates, goosefish, and seals. Commercially, little skates are used to bait lobster traps.

Barndoor Skate (Dipturus laevis) – are one of the largest skates in the area. They can reach 180 cm and over 10 kg. They eat invertebrates and fishes, including gastropods, crabs, lobsters, and polychaetes. They do not have many predators, though they are probably eaten by sharks.

Ocean Pout (Zoarces americanus) – look much like an eel with fins just behind the head. They are a yellow-green/brown with patterning on the dorsal side. They can grow to 118 cm long and more than 6 kg in weight, though the average is 40-71 cm and 0.45-1.8 kg. They eat shelled mollusks, echinoderms, and some fishes. Predators of the pout include dogfish, skates, cod, hakes, and sea ravens. Commercially, the pout was heavily marketed during World War 2. This ended when there was an outbreak of a parasitic infection in the pout resulting in an embargo on human consumption of the pout. By the late 1990s, the population was considered to be overexploited and to have low biomass.

Longhorn Sculpin (Myoxocephalus octodecemspinosus) – are greenish brown with distinct markings. They almost look armored. Large fins extend from just behind the head. Their maximum size is 45 cm but the average size is 25-35 cm. Longhorn sculpin eat shrimp, crabs, worms, mussels, mollusks, squid, fishes, etc. They are eaten by cod, spiny dogfish, skates, sea ravens, goosefish, and other sculpin. There is not currently any commercial importance.

Personal Log

Again, we were sorting and counting in the rain today. There was less wind with this storm than the last, for which I am grateful. I have also finally learned some of the tricks to shucking scallops more efficiently. Since my raingear is cuffed at both the sleeves and the pants, I have to remember to empty the water out of the cuffs before going back inside to take the gear off. During the shift, gear is left with the pants down around the boots so it is easy to get in and out of for each tow, up to 12 or more times per shift. The science crew works noon to midnight or midnight to noon while the ship’s crew works from six to six. Because of the different schedules, traditional foods for particular meals don’t happen. I am on the noon to midnight shift (day watch) and so start the day by eating lunch. Our lunch is ship’s dinner (steaks last night) and our dinner is leftovers from the kitchen, which are quite good. There are always several types of salads and one or, sometimes, two choices for a main course. Additionally, there is the candy drawer and the ice cream freezer! No one will starve out here.

June 11, 2010

June 11, 2010

Aboard: R/V Hugh R. Sharp

Weather Data at 1:35pm EDT: Clear, 14.4˚C

Location at 1:35pm EDT: Lat: 40 30.07 N Long: 69 08.66 W

Water Depth: 77.5 m

4^th Day at Sea

Why Count Sea Scallops?

That had to be the most common question I got asked before coming on this trip. Much of the information below is from the NOAA FishWatch website (www.nmfs.noaa.gov/fishwatch/species/atl_sea_scallop.htm).

Economically, sea scallops are an important species; in 2008 the scallop harvest was about 53.5 million pounds and was worth about $370 million. The population is not currently considered to be overfished and has been above minimum sustainable levels since 2001. Formal management began in 1982 with the Atlantic Sea Scallop Fisheries Management Plan. The management plan includes limiting new permits, restrictions on gear and on the number of crew on a boat. Since about 2000, the biomass of scallops has been increasing. Biomass is estimated by using the weight of scallops per tow on cruises like this one. Combinations of biomass estimates and estimates of the commercial catch are used to update and adjust the management plan.

Sea Scallops (Placopecten magellanicus) are filter feeders. They can live up to 20 years and begin reproducing at about 2 years, with maximum fertility reached at 4 years. A single female scallop can produce up to 270 million eggs in her life. This high reproductive capacity has helped the scallop population recover relatively quickly. Gender can be determined by the color of the gonad; females are orange while the male gonad is white. Adult scallops average between 6 and 7 inches from hinge to tip (called height) but can be as big as 9 inches. Age can be estimated by counting the rings on the shell. Scallops can “swim” by opening and closing the two shells. This is a useful adaptation for escaping from predators, including flounder, cod, lobsters, crabs, and sea stars. Scallops are harvested for the adductor muscle (the one that opens and closes the shell). There is no commercial aquaculture of scallops in the US as of August 2009.

Personal Log

A storm moved through beginning on Wed. evening (day 2) and stayed with us most of Thursday. By the end of shift on Wednesday, we were working on deck in full foul weather gear and life jackets. Thursday we had an 8 hour steam between dredge sites and by the end of shift on Thursday, the seas had begun to smooth out. Friday was quite nice, weather-wise.

I am learning to shuck scallops, though I am about half the speed of many on the boat. I am also learning to tell the various types of flounder and other fish apart as well. It’s not always obvious which type of founder or hake is which.

New Species

Goose fish (aka monk fish), several more varieties of flounder, sea urchins, sea cucumbers, eel pout, some very large skates, 3 types of sea stars and 1 type of brittle star.

June 8, 2010

Due to bandwidth restrictions aboard ship, pictures will be added once I am back on land.

June 8, 2010

Aboard: R/V Hugh R. Sharp

Weather Data at 6pm EDT: Calm, Clear, 23˚C

Location at 6pm EDT: Lat: 39 42.68 N Long: 73 24.98 W

Water Depth: 86.4m

First day at sea

The first day was mostly spent steaming to the first dredge site, about 14 hours away from Lewes, Delaware. In the morning, all of the safety information was covered and those of us who had not tried an exposure suit before put one on. After the ship reached the ocean, we did a test dredge to ensure that all of the equipment was working and that we all knew what to expect.

The process is basically the same for all dredges on the Sea Scallop survey. Each tow is at a specific, pre-selected random site, using the same type of dredge, at the same angle to the bottom for the same amount of time and at the same speed as all other tows. This ensures that the data gathered is comparable from tow to tow and particularly from year to year. Once the dredge is pulled back up, it is dumped onto a sorting table on the rear deck of the ship. Everything is sorted into 4 categories: scallops, fish and squid, sea habitat (which is anything that is not scallops or finfish), human trash. Once the initial sorting is done, the sea habitat is counted by the bucket-load and dumped back into the ocean; the fish are sorted by species and weighed and counted. Some species (skates, flounder/flukes, and goosefish, also called monkfish) are also measured for length. Scallops are weighed, counted and measured. Some specific samples may be kept for researchers on shore and the rest is thrown back. Human trash is kept aboard for proper disposal later. After all of the sorting and measuring is finished, the buckets are rinsed and stacked for the next dredge, which isn’t usually that long in coming.

Fortunately, we are not measuring things with a tape measure or having to manually input lengths into the computer. The ship has 3 “fish boards” that are electronic magnetic measuring devices that automatically send the data to the shipboard computers. Operators choose the species of fish being measured and then each fish is put on the board and a magnetic wand is used to mark the end of the tail of the fish. Each length is sent to the computer and stored. Historically, the data was collected on paper and the lists sent to a prison to be hand entered into a database. The database then had to be proofread and corrected if necessary. While the data still must be audited, it is much faster and easier, and less prone to error, to take the hand written stage of data collection out of the process.

Species Seen:

At the dock in Lewes: Osprey pair and at least one chick in the nest, Sea gulls

At sea: Pod of dolphins playing in the ship’s wake, jellyfish, pelicans

In the dredge: Squid, gulfstream flounder, windowpane flounder, summer flounder, spotted hake, sea robins, small skates, clearnose skates, several kinds of crabs (spider and rock), moon snails, sea stars, sand dollars, whelks, sea urchins, scallops, sea mice (polycheate worms)

Personal log:

We couldn’t have asked for better weather, clear and calm. After the safety meeting and test dredge, there was a great deal of down time until we reached the first site at about 10pm. I am on the day watch from noon to midnight and so got to sort the first real dredge. We did find scallops, ranging from about 1 inch across to about 5 inches across, but we found more sand dollars. After spending countless hours walking beaches to find even a few sand dollars, it was amazing to see hundreds or thousands on the sorting table to be tossed back as sea trash. I also discovered that you can easily loose track of time simply sitting in the sun on the deck watching the world go by.