A global map of commercial shipping, showing relative density (in color) against a black background. Ship ballast water discharge is one of the main ways invasive marine species are introduced. Courtesy of http://www.nceas.ucsb.edu/globalmarine/impacts
A global map of commercial shipping, showing relative density (in color) against a black background. Ship ballast water discharge is one of the main ways invasive marine species are introduced. Courtesy of http://www.nceas.ucsb.edu/globalmarine/impacts
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When More is not Merrier: Shifting Baselines and Invasive Species

Categories: Guest Posters

Since the early 1980’s my family has been vacationing along the St. Lawrence River in upstate New   York. We’d head up year after year to relax in the beautiful wilderness, and though I was too young to know it at the time, I was witnessing one of the worst ecological invasions of our time. The dreaded zebra mussel, now in Massachusetts, was marching through the great lakes, clearing the water of its precious plankton and forever changing the ecosystem.

But for me, the zebra mussel was just a normal part of the river while I was growing up. I thought the environment seemed healthy enough – there were birds to be seen and fish to be caught. That was because I hadn’t seen the river before the zebra mussel, they’d always been there, that was my baseline. My parents certainly remember a different river, and from their time to mine the baseline had shifted.

It wasn’t until I was much older that I saw the effect of a new invasive species in that same river, the round goby fish. I’d cast a reel and catch this funny looking bottom-feeder on rare occasions. But lately I’ve caught more and more gobies. Now I just expect them as part of the ecosystem, and one day when my kids fish in the St. Lawrence, their baseline will be filled with gobies.

The trouble is that our shifting baselines are dangerous: they cloud our idea of what’s “normal”, and they don’t allow us to see the gradual decline in the environment around us. Be it climate change, ocean acidification, pollution, overfishing, or invasive species, it can be tough to tell what “normal” used to look like.

But invasive species actually provide us with an interesting case. On one hand, if they’ve been around long enough we way think of them as part of the native community (like I did with the zebra mussel). Take, for example, the common periwinkle, Littorina littorea, an invasive species that has been around since the mid 1800’s. They’ve been here so long and they are so ubiquitous that until recently scientists have even debated whether they’re native or invasive. Surely you’ve seen these snails blanketing our rocky shores, and you too may not have thought much of them. But what did our beaches look like before they were here?

On the other hand, some species invasions allow us to witness substantial environmental changes in just a few years, and they can demonstrate to us the fragility of our ecosystems. Like the European shrimp, Palaemon elegans, which was found in Salem Sound just a couple years ago. They eat a lot of other small crustaceans, potentially shifting community interactions, and they are likely to spread rapidly along the coasts. They have already been reported in Maine, Boston Harbor, and in Rhode Island. We’ll actually be able to witness the effects of this invader in just a short while, though we can’t yet predict the severity of the impact they’ll have on native species.

With all of this change it can be easy to lose track of what’s happening in our New England waters, which is why documenting species introductions and the distributional changes of those invaders is so important. A local scientist leading the effort to detect invaders is Dr. Judy Pederson from the MIT Sea Grant College Program. Every few years she and a team of scientists perform surveys to look at the organisms (mostly attached to docks) along New England coastlines. She notes the value of a citizen monitoring program that she says has worked very well for recording invasive species.

“Part of what we do is document the presence and absence of species and their movements up and down the coast,” she told me. “But once an invasive species is found in the marine environment, it’s almost impossible to eliminate.” Since they’re so tough to get rid of, Dr. Pederson also works on helping to control the initial introduction of invaders. The most widely reported vector for spreading invasive species is the discharge of ship ballast water from foreign ports. Microscopic larvae (part of the plankton) taken into ballast water across the ocean often get released into new coastal waters where they may metamorphose and ultimately thrive. But everyday ocean-using citizens spread organisms too, which is why Dr. Pederson has worked to educate divers and boaters about cleaning their equipment after using it, lest they involuntarily transfer species to new places.

It’s a noble effort, tackling such a daunting and complicated problem. Some invasive species are even displacing previous invaders. Remember the European green crab, Carcinus maenas, whose voracious appetite isn’t very easily satiated? Though they are a menace, in some areas even these crabs are being pushed around by a relatively new (1988) invader, the Asian shore crab, Hemigrapsus sanguineus. I can’t turn over a rock at low tide without finding a few of these pugnacious little guys.

In fact, Dr. Pederson had some sobering stats: “About 15% of the species we find during our surveys are non-native, but they can be 40% of the biomass at some locations.” And the increasing effects of climate change are not likely to ease the trouble. As we’ve seen recently, the distributions of native species have been shifting, introducing New Englanders to a host of new organisms. But invaders are on the move too. The devastating lionfish has been found as far north as Narragansett Bay, and is already on the way to becoming an ecological disaster. With no known predators and native communities that aren’t adapted to recognize them as a threat, lionfish can quickly wipe out the biodiversity of entire ecosystems.

Maybe we can’t get rid of the invasive species that have taken up residence here, but without the knowledge of what used to be, we may not notice the slow changes happening all around us. We need to stay vigilant, and you can help keep a watchful eye on our oceans to remind us of how our baselines are always changing.

Casey Diederich is a 5th year PhD candidate in Tuft’s University’s Biology Department, and is conducting his research on slipper-shell snails. We are thrilled to have Casey guest blogging for us about some of the more fascinating plants and animals in our ocean. – Ed.

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.

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World Premiere of Ocean Frontiers II – A New England Story for Sustaining the Sea

How do we meet our ever-expanding demands on the ocean and also work together to protect it? The answer is explored in a new film from Green Fire Productions, Ocean Frontiers II: A New England Story for Sustaining the Sea. The second in the award-winning film series, Ocean Frontiers II is an inspiring story of citizens working together for the sake of the sea. Please join us for the premieres of this timely and important film in Providence on October 28th and in Boston on October 29th.

Ocean Frontiers II brings you face to face with those now embarking on the nation’s first regional ocean plan, promoting healthier economies and healthier seas across New England. A spotlight on Rhode Island reveals how the Ocean State turned potential conflict into collaboration, inviting all on a path of ocean stewardship. Watch the film trailer here http://ocean-frontiers.org/trailer.

The world premiere of Ocean Frontiers II is in Rhode Island on October 28th, at 7pm at the Providence Public Library. The Massachusetts premiere is the following night, October 29th, at the New England Aquarium’s IMAX theater in Boston, also at 7pm. Both events are free and open to the public, but space is limited so please make your reservation:


Providence, October 28th http://bit.ly/OceanFrontiers2RI

Boston, October 29th http://bit.ly/OceanFrontiers2Boston


Following the screening of each film we will have a short panel discussion that explores New England’s leadership to foster sustainable growth of our ocean economy and the protection and restoration of our ocean ecosystems.

You may have seen the original Ocean Frontiers: The Dawn of a New Era in Ocean Stewardship, at one of our previous screeningsOcean Frontiers is a compelling voyage to seaports and watersheds across the country to meet industrial shippers and whale biologists, pig farmers and wetland ecologists, commercial and sport fishermen and reef snorkelers—all of them embarking on a new course of cooperation to sustain the sea and our coastal and ocean economies.

Following on the heels of the award-winning Ocean Frontiers I, Green Fire Productions brings you face to face with those now embarking on the nation’s first multi-state attempt at ocean planning. Navy scientists, wind-energy executives, fishermen, Native American tribal leaders, planners and environmental advocates – all are working as one to promote healthier economies and a healthier ocean across the breadth of New England.

According to Karen Meyer, Executive Director of Green Fire Productions, “One of our goals was to make sure that people know that ocean planning is underway and that all of our voices are really critical at this stage. It’s our role as concerned citizens who are interested in coastal economies and a thriving marine ecosystem to be involved and make our voices heard.”

Please join us at one of these premieres and learn how to make your voice heard in ocean planning. In the meantime, learn more about why ocean planning matters in New England. We hope to see you at the movies!

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Caution! Electrical hazard ahead – the elusive Atlantic torpedo ray

New England waters are home to several species of elasmobranchs – or sharks, rays, and skates. Among the sharks most commonly seen in New England waters are spiny dogfish and blue sharks. Other less frequently encountered sharks are the porbeagle, mako and basking sharks.

And, although there are several types of rays in New England’s ocean, they are often much harder to observe than the sharks. Mostly camouflaged on sandy bottoms, they frequently go unnoticed. Sometimes, only their eyes will peek up above the layer of sand under which they usually hide. Generally inactive during the day, they are more frequently seen at night when they hunt.

Among the species of rays inhabiting New England coastal waters, one in particular has some rather shocking characteristics. The Atlantic torpedo ray (Torpedo nobiliana), sometimes called electric ray, is capable of discharging electrical current.

Like all electric rays, it has a pair of specialized organs that produces an electric pulse, which can be used to stun or kill prey. Each organ is composed of stacks of 500 to over 1,000 striated muscle bands all with nerves connecting on the same side. When the muscles of the organ are contracted, an electrical shock is produced. The ray’s organs store the electrical current it produces, just like a battery.

The Atlantic torpedo ray can grow up to 6 feet in length and weigh up to 200 pounds. Due to its size, this ray packs quite a punch. In fact, it is capable of producing 220 volts of electricity!

Though seldom life-threatening, the electric discharge of an Atlantic torpedo is quite severe and may be enough to render a person unconscious, not a desired state if underwater. In some cases, divers who have been shocked are said to have been disoriented.

Most divers will say that the best way to stay safe in the ocean is to refrain from touching plants or animals and this is obviously a good example of the virtues of the non-invasive observation of marine denizens.

Generally non-aggressive, the torpedo ray has few predators. Its size and stunning potential are good deterrents. It, on the other hand, feeds on bony fish, small sharks and crustaceans.

On a recent dive in Maine, at a site known as Nubble Light, we were fortunate to encounter not one but two Atlantic torpedo rays. They are easily recognizable by their disc like shape and their very small eyes.

The first ray was quite large, measuring roughly five feet in length. It was surprisingly active. We actually first spotted it as it swam past us. It seemed unbothered by our presence. We were able to get quite close without it having the urge to swim away (of course, we were very careful not to get too close). This made for good video opportunities and gave us the chance to get a close look at the animal and study its behavior during several minutes.

The second ray we encountered was smaller in size, measuring about four feet. It behaved quite differently. Completely immobile, it was perfectly content to lie on the sandy bottom. Maybe it was resting? The presence of divers nearby was of no concern to it. In fact, it was us that left it behind, at the very place we had found it.

These 2 rays were observed in less than 25 feet of water. It was late afternoon so daylight was fading and visibility was reduced due changing tides but we can still see the main features of this ray: shape and eyes.

Of our many dives at this site, we had only once before caught a quick glimpse of a Torpedo ray swimming off. This time, though, the torpedo rays were the highlight of our day.

Today’s guest post is by our friend Michel Labrecque. Michel is a published underwater photographer and contributor for various underwater medias. He is also a PADI Master Instructor, IANTD Trimix Instructor, a DAN and EFR Instructor Trainer and an HSA Instructor. He co-owns Plongée XL, a PADI 5 Star IDC Dive Center located in Victoriaville, Canada with Julie Ouimet who signs most of their articles.


Dr. Richard Kirby takes a reading as part of his global Secchi Disk Project.
Dr. Richard Kirby takes a reading as part of his global Secchi Disk Project.
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Citizen Plankton Science! Join the Secchi Disk Project (and be Extremely Awesome)

Categories: Guest Posters

So, you want to be a marine biologist but you have no training? No problem, as long as you’ve been to the eye doctor lately. Don’t have all that expensive equipment? All you’ll need is little more than your smart phone. Forget the endless hours of studying and the late nights analyzing data… Dr. Richard Kirby is giving you an easy and fun chance to contribute, and on a really important project.

Dr. Kirby is a scientist across the pond at Plymouth University’s Marine Institute and he studies plankton. We’ve taken a close look at plankton recently, both the plant and the animal variety. These sea-drifters are responsible for at least half of the oxygen we breathe, and they lie at the base of a food chain that produces hundreds of millions of tons of food for us. Their importance cannot be overstated.

But how do you study a group of organisms that are so small in size and so large in number? Well, it’s not easy, especially when you’re trying to determine the amount of phytoplankton on a global scale. Some have tried, and a widely publicized report from Nature found that phytoplankton numbers have been declining over the past century, an alarming finding given their importance. But the study has been hotly contested, and the only certain fact coming from the debate is that we need more information.

And that’s where you come in. Dr. Kirby figures the best way to get more information is to enlist the help of the roughly 7 billion amateur-scientists that may already be out at sea, whether it be working, sport fishing, or just pleasure cruising. He has developed a free mobile phone app that allows you to easily record a measure of plankton abundance from anywhere in the ocean.


The system is based around a simple little device that marine scientists have been using since 1865: the Secchi disk. Named after its inventor, Father Pietro Angelo Secchi, a Secchi disk is basically just a weighted white disk attached to a tape measure (instructions on how to make one can be found here). You lower the disk into the water and record the depth at which it disappears from sight. That is called the Secchi depth and it gives scientists a measure of how much plankton is in the water. If the water has a lot of plankton, it’ll be tougher to see the disk, and it will disappear from sight at a shallower depth.

After you determine a Secchi depth you enter it into the free Secchi App, which records your location along with the measurements that you made. All of this information is stored on your phone and passed along to Dr. Kirby once you get an internet connection. Voilà! You’re part of a major study to help figure out the changes that our world’s oceans are going through. You can even check out the data coming in from all over the world!

Our technological advances and changing climate have intersected to make this the perfect time for such an ambitious study. Dr. Kirby notes “This app enables seafarers around the world to take part in a science project and if we can just get a small percentage of the global population of sailors involved, we can generate a database that will help us understand how life in the oceans is changing. It would help us learn much more about these important organisms at a crucial time when their habitat is altering due to climate change.”

So next time you’re heading out to sea, make sure to bring your Secchi disk and your phone, and help us to understand what’s happening to our global ocean. While you’re at it, put a picture of you doing your citizen science on our Facebook page so everyone knows how awesome you are!

Casey Diederich is a 5th year PhD candidate in Tuft’s University’s Biology Department, and is conducting his research on slipper-shell snails. We are thrilled to have Casey guest blogging for us about some of the more fascinating plants and animals in our ocean. – Ed.