Ocean Currents » wildlife http://blog.oceanconservancy.org News, opinions, photos and facts from Ocean Conservancy Wed, 27 Jul 2016 17:29:16 +0000 en-US hourly 1 http://wordpress.org/?v=3.4.2 10 Things to Know About the Walrus http://blog.oceanconservancy.org/2016/05/19/10-things-to-know-about-the-walrus/ http://blog.oceanconservancy.org/2016/05/19/10-things-to-know-about-the-walrus/#comments Thu, 19 May 2016 13:30:41 +0000 Guest Blogger http://blog.oceanconservancy.org/?p=12079

This blog was written by Roger Di Silvestro, a field correspondent for Ocean Conservancy.

When you think of walruses, you may picture their tusks—the huge pinniped’s most familiar characteristic. But there is so much more to these “elephants of the sea”! Here are some less-obvious facts about these ice-dwelling creatures.

1. Biologists classify the walrus as a carnivore, or meat eater, which puts the animal in the same broad category as wolves, foxes and lions.

2. The polar bear, weighing as much as 1,200 pounds, is often touted as North America’s largest terrestrial carnivore. But it’s a mere wisp compared to the ocean-going male walrus, which can tip the scales in excess of 3,700 pounds.

3. Walruses depend on sea ice, and spend much of the summer on flows from which they dive into relatively shallow waters in search of food. In winter, the walruses go to shore and feed in near-shore waters. They communicate with grunting and roaring sounds.

4. Despite their size and their ability to stay underwater for up to half an hour, walruses are not deep divers—they usually feed at depths of less than 300 feet.

5. Walruses find much of their food by poking around on the ocean floor. When a walrus finds a tasty crab or clam buried in sand, it creates powerful suction with its mouth to vacuum it up. Walruses are not picky eaters—they feed mainly on mollusks, but will also eat worms, cephalopods, crustaceans and more. They even nosh on an occasional seal, though observations of walruses hunting their close relatives are rare.

6. Walruses are able to locate buried food thanks to the 400-700 stiff bristles, or vibrissae, which grow on their muzzles. Like a cat’s whiskers, vibrissae are sensitive to touch, telling the walrus when it has come in contact with an appropriate food. Vibrissae can grow up to a foot long, but scraping against sand and rock usually keeps them shorter.

7. Adult walruses have few enemies, mostly due to their massive size and sharp tusks, which can grow to more than three feet long. Bears sometimes attack young walruses, as do orcas. A bear attack on a beached walrus herd can make the pinnipeds rush headlong for the safety of water, causing injuries to adult walruses in the general crush and making them vulnerable to bear attacks.

8. The scientific name for the walrus genus is Odobenus, which is Greek for “tooth walker,” so-called because walruses sometimes use their tusks to haul themselves onto ice.

9. The brownish, heavily seamed skin of the walrus is over 1.5 inches thick and covers a layer of blubber that can get to 3.9 inches thick.  The skin grows paler as the animals age, until the dark brown of the young fades to cinnamon in mature animals. The color depends partly on blood flow to the skin; when in cold water, blood flow to the skin reduces, so the skin of a pink walrus can turn nearly white.

10. Walruses breed from January to March while winter is in full swing, and females give birth about 16 months later. A newborn calf can weigh 100 to 165 pounds and may stay with the mother for two years or more, though usually weaned after a year.

The Ocean Conservancy is using science-based solutions to tackle the biggest threats to our ocean, including ones that threaten walruses and other wildlife. See how you can take action.

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Arctic Wildlife: Get to Know the Insect of the Sea, Arctic Copepods http://blog.oceanconservancy.org/2016/04/07/arctic-wildlife-get-to-know-the-insect-of-the-sea-arctic-copepods/ http://blog.oceanconservancy.org/2016/04/07/arctic-wildlife-get-to-know-the-insect-of-the-sea-arctic-copepods/#comments Thu, 07 Apr 2016 12:00:44 +0000 Becca Robbins Gisclair http://blog.oceanconservancy.org/?p=11873

Our blog series on the lesser known (but just as cool) species of the Arctic continues with Arctic copepods. Read our other blogs from the series: polar cod and brittle stars.

I’ve always loved ribbon seals, narwhals and ringed seals to name a few cute Arctic creatures. While these beautiful animals get all the glory, they wouldn’t be around for these important little guys at the base of the food chain: meet the copepod!

“Copepod” means oar-footed, and that is how these aquatic crustaceans, often called “insects of the sea” move around. They use their four to five pairs of legs as well as their mouth and tail to swim. In the Arctic, copepods live on the seafloor, in the water column and on the sea ice. In the water column, there are more copepods than any other multi-cellular organism.

Copepods come in many forms—some are filter feeders, some are predators. Copepods have two major life forms and grow by shedding their shell. They go through 12 stages after hatching—that’s a lot of wardrobe changes! By our standards, copepods are tiny, measuring in at 0.3 to 2cm long at full size.

Here’s what lots of copepods look like! (From a Bowhead whale stomach)

In the Arctic there are over 150 species of copepods. The most abundant and largest is Calanus hyperboreus, a filter feeder with red highlights on its antennae. These copepods have a reproductive cycle uniquely adapted to life in the Arctic, using the dark Arctic night for romance. In the deep of winter, males fertilize the females and then die off. Females then survive on stored up reserves of large fat deposits to make it through the winter.

Copepods are the critical base of the food chain in the Arctic. Some large mammals such as bowhead whales, eat copepods directly. Here is what a whole lot of copepods from the stomach of a Bowhead whale look like (picture to the right). Fish species, such as the polar cod, also eat copepods. Other marine mammals, such as my beloved favorite the ribbon seal, then eat the polar cod. While they might not be as cute and snuggly as the larger, more charismatic critters who depend on them, the copepod is the essential foundation for life in the Arctic.

Learn how you can help protect copepods and the vast diversity of wildlife who call the Arctic home.

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Arctic Wildlife: Get to Know Brittle Stars http://blog.oceanconservancy.org/2016/03/30/arctic-wildlife-get-to-know-brittle-stars/ http://blog.oceanconservancy.org/2016/03/30/arctic-wildlife-get-to-know-brittle-stars/#comments Wed, 30 Mar 2016 12:28:48 +0000 Sarah Bobbe http://blog.oceanconservancy.org/?p=11748

Our blog series on the lesser known (but just as cool) species of the Arctic continues with brittle stars. Read our other blogs from the series: polar cod and Arctic copepods.

Brittle stars are seafloor dwelling organisms that appear to be a quirkier, more slender version of a starfish. Although they are closely related to starfish—brittle stars differ in many ways.

Brittle stars have a distinct central disc and (usually) five skinny, flexible arms. The central disk (approximately 2.5 cm in diameter in the species Ophiura sarsii) consists of a skeleton of calcium carbonate and contains all the brittle stars’ internal organs. The disk’s appending five arms (circa 9 cm long in Ophiura sarsii) twist and coil to enable movement across the seafloor. Not only do their arms enable locomotion: brittle stars can purposely release on or move arms to evade a predator! As long as its central disk remains, the brittle star will continue to function, and its limbs will regenerate.

Brittle stars occupy a variety of habitats in all oceans of the world. There are an estimated 73 brittle star species that call the waters of the Arctic home. The brittle stars of the Arctic live at various depths, with some species occurring deeper than 3,500m. The largest observed assemblages in the Alaskan Arctic occur on shallower ocean shelf waters, and generally consist of Ophiura sarsii and Ophiocten sericeum brittle star species.

Brittle stars play an important role in the Arctic food web. First, they are known to be seafloor ecosystem engineers. They reshape the seafloor sediment surface and influence the distribution of other seafloor species. They also provide nutrition to fish, sea stars and crab predators. Brittle stars themselves are known to consume small organisms, feed on detrius, and/or filter feed organisms from ocean water. The mouth of brittle star, which is located on the underbelly of its disk, contains five jaws.

If you thought detachable arms was crazy, check out the alien-like Gorgonocephalus acticus. The Gorgonocephalus acticus is a basket star, a taxon of brittle stars that live in the deep waters of the Arctic. The five arms of this species repeatedly branch into smaller and smaller subdivisions, giving it a medusa-like appearance. In fact, its name means “dreaded head” in Greek and refers to Medusa and her two sisters, whose hair was made of living snakes. This species is also much larger than most brittle stars (as show in the image below).

Although I adore polar bears and walrus, it is my hope brittle stars and the lesser-known (and in this case, quirkier) species residing in the Arctic receive their day in the spotlight and become known for the role they play in the fragile Arctic ecosystem. Please join me in celebrating one of many unsung (and stranger) classes of the Arctic ecosystem by sharing your enthusiasm for the brittle star!

Learn how you can help protect brittle stars and the vast diversity of wildlife who call the Arctic home.

 

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Arctic Wildlife: Get to Know the Polar Cod http://blog.oceanconservancy.org/2016/03/23/arctic-wildlife-get-to-know-the-polar-cod/ http://blog.oceanconservancy.org/2016/03/23/arctic-wildlife-get-to-know-the-polar-cod/#comments Wed, 23 Mar 2016 12:31:34 +0000 Todd Stevenson http://blog.oceanconservancy.org/?p=11736

Join us as we dive into the chilly waters of the Arctic. Our blog series explores the magnificent (and often overlooked) species living in the Arctic—which you need to know! Read our other blogs from the series: brittle stars and Arctic copepods.

When most of us think of important Arctic marine species, we generally think of walrus, narwhal, seal, beluga and others. Although those species capture our imagination and are special to the Arctic, there are a number of lesser known species that may not have the same charisma but are equally, if not more, important for helping maintain the Arctic marine ecosystem. As a person who has always loved marine fishes, I’ve long thought polar cod (Boreogadus saida) are an exceptionally fascinating Arctic fish that just does not receive the attention it should.

Polar cod are one of the most abundant fish in the circumpolar Arctic, occurring in all corners of the region in sub-zero waters. They are able to thrive in such cold waters because they produce glycoproteins that serve as an antifreeze in their blood—an amazing evolutionary feat. Large schools of polar cod can sometimes feed so aggressively that they can cause local depletions of zooplankton populations. Polar cod are highly efficient in converting ingested prey into growth and become sexually mature within 2-3 years. Even though this is an incredibly short period of time, it allows them to get large enough to serve as a very important high energy food source for many large mammals in the Arctic (e.g., ringed seal (Pusa hispida), narwhal (Monodon monoceros), white whale (Delphinapterus leucas)) and seabirds (e.g., Brünnich’s guillemot (Uria lomvia), Black guillemot (Cepphus grylle), and Northern fulmar (Fulmarus glacialis)).

Polar cod can be found in a diverse range of Arctic habitats during different stages of life, including open and nearshore waters, shallow and deep waters, brackish lagoons, river mouths, and other habitats, and they are also the only fish species residing inside the Arctic ice pack! At one time polar cod were harvested in large numbers and converted to fishmeal and fish oil by countries such as the Russia, Norway, Germany and Denmark.

The pack-ice is an important habitat for polar cod during their first- and second-year of life, and it serves as a safe haven from marine mammals and sea birds that prey on them. The reproductive success of polar cod is also directly related to formation and break-up of seasonal polar ice. The dependence polar cod have on sea ice habitat is a double-edge sword. On one side they are well protected from predators and there are no other fish they compete with in those icy environments. On the flip side, the Arctic is warming twice as fast as the global average as a result from climate change and sea ice habitats are rapidly disappearing. The failure of sea ice formation will challenge the long-term survival of polar cod in the Arctic. Diminishing sea ice habitats will negatively impact polar cod reproduction and thus abundance, which will influence the distribution, abundance, and predator-prey interactions of other species that rely on them. As water temperature warms in the Arctic, sub-Arctic species will expand their range northward and compete with polar cod. Competition with other sub-Arctic species may further complicate the long term survival of polar cod, and if they are locally or regionally extirpated, the Arctic food web and ecosystem as we know it today will change forever.

The ability for polar cod to evolve and thrive in such harsh, cold water environments and to serve as such an important prey source to so many charismatic Arctic fauna makes them an unbelievably important species that unfortunately does not receive ample global attention.

It’s my hope that the polar cod will finally receive the praise and attention that they so aptly deserve! After all—it’s thanks to the polar cod that the charismatic narwhals and ringed seals are able to survive.

Learn how you can help protect polar cod and the vast diversity of wildlife who call the Arctic home.

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BP Trial Highlights Lasting Offshore Impacts in the Gulf http://blog.oceanconservancy.org/2015/02/02/bp-trial-highlights-lasting-offshore-impacts-in-the-gulf/ http://blog.oceanconservancy.org/2015/02/02/bp-trial-highlights-lasting-offshore-impacts-in-the-gulf/#comments Mon, 02 Feb 2015 15:09:00 +0000 Libby Fetherston http://blog.oceanconservancy.org/?p=9775

Last week during the ongoing BP trial in New Orleans, the testimony of Donald Boesch, a professor of marine science at the University of Maryland, was a real call-to-arms for ocean-lovers. Much of the impact to marine fish, habitats and wildlife has been “out of sight, out of mind” and in many cases off limits to the public.

Through Boesch’s testimony, the U.S. prosecutors hope to highlight the seriousness of the BP Deepwater Horizon oil disaster—one of eight factors that will determine the level of environmental fines the judge will set—and make the case for fines as high as $13.7 billion. Boesch painted an alarming picture of potential marine impacts, with deep-water corals and other living creatures on the seabed of the Gulf covered in oil.

Dolphins are suffering from lung disease and low weight. Sargassum, the floating seaweed essential to juvenile sea turtles and schooling fish, was coated in oil and sank under the weight. Plankton, bacteria, protozoans, and tiny crustaceans drifting on or near the surface of water – the foundation of the Gulf’s food web – had no means to escape the toxic plume of dispersants and oil. Hundreds of thousands of sea birds and shore birds including pelicans, gulls, and gannets are presumed dead, the vast majority of which sank to the seafloor or wound up in other unreachable parts of the Gulf.

“We don’t know fully about the recoverability of these species – it’s a slow process,” Boesch said. “Something we don’t yet know is how long this effect will last.”

The work and testimony of scientists like Dr. Boesch are beginning to shed light on how severely the Gulf was hit, and give new urgency to recovery through restoration investments and solving chronic sources of stress and degradation (e.g., overfishing, pollution, the dead zone, coastal erosion, habitat destruction).

Fortunately, these marine impacts can be remedied. Restoration programs are finally underway, and with smart investment strategies, we can recover and restore what was lost in the Gulf beyond the shore. Only 9 percent of the total funding for projects go toward restoring the marine wildlife and habitats of the Gulf. We can change this number by ensuring that restoration following the BP trial includes the marine environment, where the oil disaster began.

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One of the Biggest Arctic Migrations You’ve Never Heard of http://blog.oceanconservancy.org/2014/05/12/one-of-natures-wonders-spring-migration-in-the-arctic/ http://blog.oceanconservancy.org/2014/05/12/one-of-natures-wonders-spring-migration-in-the-arctic/#comments Mon, 12 May 2014 16:29:11 +0000 Carmen Yeung http://blog.oceanconservancy.org/?p=8265

Photo Credit: NOAA National Marine Mammal Laboratory

Ocean Conservancy will be publishing a blog series exploring the wonder of the Bering Strait and highlighting threats and solutions to this region.

The Bering Strait—located between Alaska’s Seward Peninsula and Russia’s Chukotka Peninsula—is the only marine gateway connecting the Arctic Ocean and Pacific Ocean. At its narrowest point, the strait is just 55 miles wide. Big Diomede Island (Russia) and Little Diomede Island (U.S.) are located near the middle of the Bering Strait, and are separated by a strip of water less than three miles wide. Despite its cold, remote location, the Bering Strait is a key biological hotspot, a region that contains a significant number of species – some of which are found nowhere else on Earth. This strait is both a bottleneck and a pathway for marine life.

In the middle of the Bering Strait, Big Diomede Island is located to the west and Little Diomede Island is to the east.

Each spring, millions of seabirds and hundreds of thousands of marine mammals traverse the narrow strait as they migrate to the Arctic Ocean. Sea ice—frozen seawater that floats on the ocean surface—plays a major role in this seasonal migration. In the spring, migratory birds and marine mammals gather in the Bering Sea and follow the retreating ice edge north through the Bering Strait and into the Chukchi Sea and the Arctic Ocean. The ice edge is highly productive, and the sea ice itself provides important habitat for microorganisms, birds and marine mammals. The Bering and Chukchi Seas are one of the most productive ocean ecosystems in the world.

Photo Credit: NASA, May 2000

Photo Credit: NASA, August 2000

Four species of ice-dependent seals—bearded, ribbon, ringed and spotted—use the sea ice for resting and as a platform from which to feed on prey like fish, shrimp and crabs. Polar bears and Pacific walruses hunt and feed on or from the sea ice. Open areas of the ice—called leads or polynyas—attract dozens of bird species, including the short-tailed albatross, spectacled eider and Steller’s eider. These and other bird species use the Bering Strait’s rich waters for foraging and as a pathway to the summer habitat in the Arctic.

Photo Credit: NOAA Fisheries

Under the chilly spring water, nearly 10,500 bowhead whales follow leads in the sea ice as they move north through the narrow passage of the Bering. These rotund black whales use their enormous heads to break through thick sea ice. Their common name originates from their bow-shaped skulls, which are over 16.5 feet long and about 35 percent of their total adult body length. In addition to bowhead whales, beluga and gray whales travel through the Being Strait on their way north to raise their young or feed.

With huge pulses of birds and marine mammals passing through this gateway from the Pacific to the Arctic each year, spring migration in the Bering Strait is truly one of nature’s wonders. There is no question that this narrow and biologically rich stretch of water is critically important, not only to Arctic species like walruses, bowheads and spectacled eiders, but also to wider-ranging species like gray whales and migratory seabirds.

The yearly migrations of marine mammals are essential to people living in Bering Strait communities and beyond. People living in the region’s communities rely on the continued productivity of the region’s marine ecosystem to support their subsistence way of life and cultural traditions as well as to meet other economic and community needs.

Of course, fish, birds, marine mammals, and subsistence hunters do not have a monopoly on the Bering Strait. As the retreat of summer sea ice in the Arctic Ocean has accelerated, the region is attracting more attention from industry. There is growing interest in shipping, oil and gas exploration, tourism and other commercial activities that contribute to increasing levels of vessel traffic through the Bering Strait. Increased traffic in this fragile ocean space could result in more pollution, ship strikes on marine mammals, as well as chronic and catastrophic oil spills among other potential impacts to the marine environment. The Bering Strait region is particularly vulnerable because it is home to such high concentrations of wildlife. We’ll explore these issues—and potential solutions—in future blog posts.

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Gulf of Maine Cleanups Show Ocean Trash Is Global Problem With Local Impacts, Solutions http://blog.oceanconservancy.org/2013/08/28/gulf-of-maine-cleanups-show-ocean-trash-is-global-problem-with-local-impacts-solutions/ http://blog.oceanconservancy.org/2013/08/28/gulf-of-maine-cleanups-show-ocean-trash-is-global-problem-with-local-impacts-solutions/#comments Wed, 28 Aug 2013 21:50:18 +0000 Allison Schutes http://blog.oceanconservancy.org/?p=6565 Scientist aboard American Promise empties a net full of marine debris

Photo: Allison Schutes / Ocean Conservancy

200 miles, 7 beaches, 4 islands and over 7,500 pieces of trash: These numbers can be used to describe my time with Rozalia Project in the Gulf of Maine. But they don’t tell the whole story. Instead “inspiring” seems to capture most of my emotions.

Incredible scenery and wildlife served as the backdrop for the long days we spent collecting and removing trash while living aboard American Promise. Not only were we surrounded by a large pod of Atlantic white-sided dolphins as we sailed south from Hurricane Island, but we also had a finback whale come within 5 meters of the boat at sunset. We saw the spouts of another whale in the moonlight reflecting off the ocean, and we observed harbor porpoises and seals, a pair of bald eagles and even an ocean sunfish, or Mola mola, in Gosport Harbor.

Our crew of 10—eight people and two dogs—were united with one goal: to remove as much trash from the shoreline and ocean surface as possible while recording data about each and every item we removed. Sailing from Bar Harbor to Kittery, Maine, we conducted seven shoreline cleanups on four different islands, and aboard American Promise, we performed three Neuston net tows and multiple dip-net sessions—all resulting in the collection of a lot of trash.

Despite traveling to several remote islands off Maine’s rocky coast, we found many of the same items that top our list during the International Coastal Cleanup every year. Items like food wrappers, plastic beverage bottles, foam cups and plates, and bottle caps were prevalent on almost every cleanup conducted while sailing through the Gulf of Maine.

These results are not incredibly surprising because we know that trash travels. Whether carried by the wind, current or human hands, everyday trash is able to make its way to even the most remote of places. For example, I pulled a food wrapper, a cigarette butt and a strap for sunglasses out of the water while sailing 50 miles off the coast of Portland, Maine.

Yet during this journey, single use plastic items were not our biggest finds. Fishing gear, including rope, monofilament line, fishing buoys, pots and traps, and lobster claw bands topped our list of items collected through the entire journey. We even found lobster bands, bleach and beverage bottles with French labels and markings, indicating these items may have started their journey in Canada.

All of these data are further indicative that ocean trash is a global problem with local impacts and local solutions. We all have a role to play in combating ocean trash, and joining us for the 28th International Coastal Cleanup is a great place to start.

Want to get started before the Cleanup? Take the pledge to help turn the tide on ocean trash.

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