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A Boatful of Thankful – Mantis shrimp, Greenland Sharks, and Kids who Love the Ocean

As we approach our national day of gratitude and binge eating, I wanted to say a big heartfelt “thank you” to my muses, the ocean and the people who geek out on it. Here, in no particular order, are just some of the things in and around the sea that I am truly thankful for, and that make the ocean beat the most interesting one on the planet.

 

  • Mantis shrimp: “One of the most creatively violent animals on the planet.” If you haven’t been introduced to these little guys, or to The Oatmeal cartoon about them - now is the time.

 

  • Greenland sharks or, as they are affectionately known, “Canada’s crocodile.” Slow, small-brained, and often blind from eyeball parasites – they still manage to eat large, fast mammals. In fact, one of them took Greenland sharking to a new level recently by taking on a huge hunk of moose meat in Newfoundland. It did not go well, but fortunately some folks were there to help the shark out of its jam when the moose got stuck.  So, I’m thankful for Greenland sharks and for Newfoundlanders cause DANG that is a uniquely Canadian and impressive feat – yanking a huge hunk of moose hide out of a beached shark. A tip of the hat to you all.

 

  • Squid, cuttlefish, octopi – masters of camouflage and the creatures that make me ponder what evolution has in store for humans. If these guys figure out how to take to land I’m not sure we stand much of a chance. I know other people are worried too – because our SciFi aliens often resemble cephalopods.

 

 

 

  • Cashes Ledge. There is a place in New England that looks like a NorCal giant kelp forest, full of all the best kinds of things in the sea (including wolffish). Help us protect it!

 

  • Surfing. If you surf, you know. If you don’t, I can’t explain it without sounding like a total, well, like this guy. Just go try it. And, while we’re on the subject of surfing:

 

  • Great white sharks. They keep us on our toes. (Literally – I would rather be riding a wave then dangling my shark-bait feet in the water off my board). They also inspire awe and wonder, and really funny memes.

 

 

  • My family. They let me tell all these fantastic tales around the dinner table, help me pull out the juiciest details, and give me ideas for stories I never thought of. My kids can now beat most grownups at “ocean trivia.” Proud mom.

 

 

Mahalo to you all!

Lined Seahorse- Hippocampus erectus
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Cool Fish, Hot Water: Seahorses Swim North

Categories: Ocean Oddities

New England’s ocean is getting warmer—and the fish are headed north.

In 2012, water temperatures in the Gulf of Maine reached record high temperatures. NOAA reports that sea surface temperatures in some areas were as much as 11 degrees Fahrenheit above long-term averages, while deep waters were about 3 degrees  higher than average. Temperatures in the first half of 2013 were less extreme, but remained unusually warm. The high temperatures of the past two years aren’t a new development, either—the Gulf of Maine has experienced a long-term warming trend for well over a century.

While these balmy temperatures may be nice for swimmers and surfers, their effect on marine life might not be as positive. The impacts of climate change on the health of marine species are still uncertain, although scientists are beginning to understand how warmer temperatures cause plankton to bloom earlier, help invasive species like green crabs thrive, may cause fish to grow to smaller sizes, and push commercially important species like cod to cooler, deeper waters.

One effect of warming waters in New England has been very clear, though. As ocean temperatures around Cape Cod and in the Gulf of Maine reach record highs, fishermen have started to notice some unusual species on their lines and in their nets—species more typical of warmer waters in the mid-Atlantic or even the tropical ecosystem of the Caribbean. Over the next several posts in this series, we’ll introduce you to some of these new faces.

Our first species—perhaps the most startling example of a once-subtropical species showing up in the Gulf of Maine—is the common seahorse, Hippocampus erectus (also known as Hippocampus hudsonius). Although their range does extend as far north as Nova Scotia, these familiar fish were once only common from the Chesapeake Bay to the Venezuelan coast, and were almost never found in the Gulf of Maine. Most people probably associate these fish with snorkeling on a reef or the tropical tank at the aquarium. But last summer, at least one Maine lobsterman, David Cousens, pulled up several seahorses in his lobster traps—something he’d never seen before.

The evidence for warm-water fish species moving north isn’t just anecdotal. Several scientific studies over the past five years have shown strong evidence that fish distribution is changing in response to climate change. In 2009, scientists from the National Marine Fisheries Service tracked the center points of the populations of 36 fish stocks and found that between 1968 and 2007, nearly all of these species moved north or shifted to deeper water. In 2012, a group of scientists developed an index called the Mean Temperature of Catch, or MTC, which is calculated as the average “preferred temperature” of the species caught in an area. Worldwide, MTC has increased steadily since at least the 1970s, suggesting that global fisheries are catching more species that prefer warmer water.

Most recently, an article published in Science shows that the direction and speed at which the distribution of species changes closely tracks the direction and speed of the effects of climate change. This does not always mean that species move north—off California, for example, stronger winds have pushed cooler waters south, and fish have moved south, too—but it does mean that marine species are redistributing to follow cooler water as temperatures change. In New England, cooler waters are moving north and offshore, and that’s where the fish are headed, too.

Stay tuned over the next several weeks as we introduce you to some of the species that have started calling New England home as our water temperatures rise. These profiles will just skim the surface of the fish moving in to this region—everything from grouper to vivid tropical species like filefish has been spotted in this area in the past few years, and these changes may just be beginning. Whether a beachgoer, a diver, or a fisherman, we will all have to adapt to the changing environment and new species in the Gulf of Maine.

Blue whale with calf. Image credit Andreas Tille.
Blue whale with calf. Image credit Andreas Tille.
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Blue whale ears – more than meets the eye

What’s the first animal that comes to mind when you think of New England’s ocean? Cod? Striped bass? Maybe great white sharks? For me, lately, it’s been the biggest of all the animals that have ever existed – the blue whale. Bigger than any dinosaur that ever pounded the planet or huge ancient shark* that patrolled the warm, primordial sea, their tongues alone weigh as much as an elephant. These leviathans can weigh over 300,000 pounds. You could swim through their heart (but please don’t try).

We may not see them very often, but these endangered animals cruise by here pretty regularly. Why? They take advantage of our very productive waters to fatten up on tiny shrimp-like krill for their long migration from near the poles toward the equator.

Like some of our other, more frequently encountered leviathans, the North Atlantic right whales, blue whales head south for the winter to have their huge babies, but there’s not enough to eat down there (why do you think the water is so clear?), so they head back up when the calves are ready to travel.

Let’s talk about those huge calves for a minute. They measure over 20 feet long, drink about 150 gallons of milk each day from a mother who is on a diet (due to the poor feeding options in the warm calving grounds), and they double in length within 6 months.

That’s all pretty cool, but I know what you’re thinking – why I haven’t talked about anything weird or gross yet? Well, here it is, hot of the presses, new whale ear wax science!

Blue whales’ ears make a long, candle-stick shaped plug of wax throughout the whales lifetime (see below). Scientist are unsure of its function – it might help the whale hear better by channeling the low frequency noises they communicate with to the eardrum.

 

The whale earplug used in the study. Photo credit: Baylor.edu http://www.baylor.edu/mediacommunications/news.php?action=story&story=132825

The whale earplug used in the study. Photo credit: Baylor.edu

 

The wax has “rings” like a tree trunk. There are darker colored rings when the whale is migrating and eating very little, and lighter colored ones when the whale is feasting. This can give scientists big clues about the age of the animal when they harvest the wax from already dead animals. Already pretty interesting, right? But when two scientists at Baylor University recently dug into the biochemistry of the earplug – a novel picture started to emerge.

The wax carries a chemical record of the whale’s life, arranged by year. Hormones produced in the whale’s body are archived in the wax. So the researchers were able to put together never-before recorded pattern of yearly reproductive development and production of stress hormones. Not only that, but pollutants like mercury and pesticides can also be detected in the earplug, giving researchers an idea of what year the whale was exposed to them.

“You have this 100-year-old question: How are we impacting these animals? There is ship traffic, environmental noise, climate change and contaminants. Now, we are able to provide definitive answers by analyzing whale earwax plugs,” said Dr. Sascha Usenko, one of the scientists who developed this technique.

The best part – while the science being used to study the ear wax is new, scientists have been collecting the ear plugs for decades from animals that have been found all over the world. So, knowing the date an animal was found and its age, researchers can figure out what kinds of chemicals the animal was exposed to and possibly link this to our activities on land (for example, increased coal burning or pesticide use), helping us piece together just how much we’re changing this big pond of ours. And, hopefully, we can think even more about how to stop dumping so much ick into our air and water.

Whatever we decide to do with the knowledge – this is a huge new story about the ocean just waiting to be told, from the whales’ ears to ours.

* Please note: megalodons are very extinct, regardless of the Discovery Channels claims to the contrary.

NEFSC researcher Larry Alade holds a tagged monkfish
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Monkfish Look Like They Could Bite Your Foot Off

This fish looks like it was designed by Stephen King, with its angular gaping mouth, needle-like teeth, and beady eyes. Imagine your reaction if you were enjoying a refreshing dip in the ocean then you looked down and saw that face staring up at you. I pride myself on surfing with the sharks in the bracing New England ocean, but seeing that crazy face by my feet might just leave me unhinged for a minute. These fish range throughout the North Atlantic, and as far south as Florida, so I know they’re around.

Really, though, your odds of encountering a monkfish are very low and if you did, they probably wouldn’t attack you. They usually hang out on the ocean floor, where they lie in wait, lure in prey with a filament-like “esca” that sprouts from between their eyes, and snatch up whatever unfortunate little fish happens to show interest.

As effective as this strategy seems to be, this bottom-dweller does get up near the surface every now and then – to eat birds. Researchers have recently discovered little puffins in the bellies of monkfish that were caught between 275 and 495 feet down, off the coast of Chatham, MA. Monkfish fish get around! And, I will confess, I didn’t even know we had puffins in New England.

I would really love to see some Crittercam  footage of a monkfish swimming up from the dark, cold depths and rushing a cute little unsuspecting puffin. Pow! Like a shark attack, but smaller and uglier. I’m going to be thinking about this the next time my feet are dangling off my surfboard (although researchers think the puffins were diving down 10 or 20 feet when the monkfish nabbed them). Still – as if the shark anxiety wasn’t bad enough.

Here are some other interesting monkfish facts (these and more can be found in this fact sheet from World Wildlife Fund).

  • Monkfish are also called goosefish, bellyfish, allmouth, and lawyer (that last one seems a little harsh).
  • These fish have been found almost 3,000 feet down.
  • They can eat things larger than they are, and are not very picky. Cod, lobster, and birds are all fair game.
  • Monkfish was not considered marketable in the U.S., until a government funded marketing campaign convinced people they were missing out on something that Europeans had been onto for a while.

Julia Child and a large monkfish. © copyright 2000-2007 Getty Images, Inc. [Steve Hansen/TimePix]

Julia Child and a large monkfish. Copyright 2000-2007 Getty Images, Inc. [Steve Hansen/TimePix]

 While monkfish have yet to show any interest in eating us, we do seem to enjoy eating them. In New England alone, commercial landings have averaged 35 million pounds a year since 1990. Hopefully this important and unique Gulf of Maine dweller will be able to withstand the  fishing pressure that is now upon them. Given the state of collapse of our cod fishery, healthier bottom dwelling fish stocks are being increasingly targeted to help sustain the fleet. This sort of action might backfire if populations of monkfish and other groundfish begin to plummet as the cod have, leaving fishermen with less and less. Worse, there are pressures on groundfish other than fishing, like warming seas and ocean acidification, which make it important that we set some habitat aside for our ocean ecosystems to adapt and build resiliency to our changing environment.

As odd looking and voracious as monkfish are, they are an important part of our New England ocean ecosystem. I hope that our fisheries managers and researches keep tabs on monkfish populations so we don’t imperil this true ocean oddity. Especially since I haven’t seen that Crittercam footage yet.

Sheepshead Fish Teeth
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Sheepshead Fish are a True Ocean Oddity

April is National Humor Month, so here’s some evidence that nature can tell a good joke. Meet the sheepshead fish. I can tell you all about where it lives, how big it gets, all the usual statistics. But wouldn’t you rather know about those teeth?

Sheepshead fish eat all kinds of things – from soft-bodied marine worms to clams and barnacles – so they need teeth that can accommodate this dietary range. Teeth like ours, as it turns out (although I’m not sure we could crunch up a clam shell). They also have a bonus feature we lack –  extra rows behind the front teeth.

Crazy teeth aside, they are a pretty attractive looking fish, with vertical black and silver stripes that have earned them the nickname “convict fish.”

Photo credit: Virginia Institute of Marine Science

Photo credit: Virginia Institute of Marine Science

These odd little fish are actually quite common – ranging from Cape Cod to Florida. In spite of the impressive looking chompers, they only get to be about 30 inches long, and 15 pounds. I hear they are tasty and popular with recreational fishermen, but I’m not sure I could get past those teeth.