ocean – Page 2 – 2022 Archive of RENATURED, Marina Zurkow's Research Blog

June 13, 2009June 13, 2009

Chinese Mitten Crabs

Chinese mitten crab. Image courtesy of the New Zealand Ministry of Fisheries.

The Chinese mitten crab is a native of East Asia, introduced into Europe in the 1930s. It is thought to have been transported to Britain in ships’ ballast water (juvenile crabs and larvae) or perhaps by adult crabs clinging to ships’ hulls. The species has six larval development stages and it is understood that for complete development the larvae need to migrate to the open sea. Dispersion of the species is assisted by the pelagic larvae and mobile adults. Adults live in freshwater migrating to river estuaries and coastal regions to breed.

From the site, Marine Aliens:

The Chinese mitten crab has increased markedly in the last 10 years in the UK. This invasive species can cause serious structural degradation and pose a significant threat to native communities in estuarine systems. As a consequence, it has been placed on the IUCN 100 of the World’s worst invasive alien species list. The largest UK population of mitten crabs is located in the Thames region, including the Medway and Blackwater estuaries. This species has also been reported from the Humber and Tyne. Click here for video footage of the Chinese mitten crab.

Chinese Mitten Crabs(大闸蟹).

A Chinese delicacy, especially when their gonads are enlarged, “They are considered as the best yummies of the Southern Yangtze River.” It appears they live in freshwater but migrate to the sea in the fall to mate – a time in which the femailes are “very plump.” (http://www.iwalku2.com/2008/10/its-season-of-yangcheng-lake-mitten-crab.html)

June 12, 2009June 12, 2009

Grant Burgess, The DOVE Marine Laboratory

I had a tour, some lessons and an intense conversation with Grant Burgess, Director of the DOVE Marine Laboratory in Cullercoats, Northumberland (it’s part of Newcastle University’s Marine Biology Dept).

This is one of the few labs that has a steady supply of seawater pumped through the building’s plumbing. It flows through the lab taps!

I learned a bit about Anton Dohrn, who built the first Marine Station in Naples in the 1870’s, and actually implemented an art-science interface, by hosting concerts, and art events within the lab… Grant came to my talk at ISIS, and is clearly very open to the interplay of hard science, and the evocations that art can muster, measures to teach and incite…

Grant’s lab foci include: “Novel bioactive compounds from marine bacteria, chemical defense in marine microbes, antifouling compounds from marine bacteria, microbiology at high pressure, sponge microbiology, biofilms, and more recently marine fermentation and bioprocessing.”

In lay terms, he explained that the lab’s working on turning algae/fungus into an OMEGA 6 source, since we no longer have fish as a viable source for the nutrients; and using algae as an energy fuels. The lab also researches the medicinal potential of sea slugs, and ways to zap ballast water of invasive species. Among other things. I got a crash course in quorum sensing– the ways bacteria make language out of molecular signaling, in order to act in concert when a quorum is reached.

The lab’s growing algae on the roof ( even in winter in the limited sunlight) in these cheerful, workaday aquaria:

We took a tour through the remains of the Victorian era public aquarium, where we met a very curious plaice, who came right up to the window, very self-possessed and clearly eager. Am I anthropomorphizing? Is it useful? Can one attribute motivation without human descriptors, and attribute thoughtful agency to non-human animals?

We also had some very speculative conversations on invasive species – the embedded racism and selective designations inherent in the condemnatory term, and how the line is in slippery flux between “introduced” and “invasive.”

I like these hybrid spaces – of thinking, working, making.

May 21, 2009May 21, 2009

cyanobacteria is burning

A nasty sea weed, Lyngbya majuscula is thriving from Tampa Bay to Sidney.

It’s not a weed – though it’s known as fireweed; it’s actually a “a benthic filamentous marine cyanobacterium” (National Research Centre for Environmental Toxicology) that grows on seagrass, and it does very well in low-oxygen environments, ripe for a bloom when there are not so many fish to stave its spread.

Its effects are toxic to humans- (itchy rashes, painful boils, and respiratory problems on exposure)

It is also known as Mermaids Hair.

When Lyngbya grows in sufficient mass it will detach from the substrate, seagrass beds and other areas where it typically grows and form floating ‘rafts’ which are then moved by prevailing winds and currents in the bay and eventually onto foreshores. (Redlands, Australia)

A raft of Lyngbya majuscula

LA Times’ environmental reporting is very good, but very apocalyptic. I didn’t say “hyperbole.”
July 2006 LA Times “A Primeval Tide of Toxins”

April 12, 2009April 23, 2009

Charismatic megafauna: you can’t live without ’em.

“Giant pandas are ‘charismatic megafauna,’ a category that includes whales and other sea mammals, salmon and other inspirational fish, eagles and other flashy raptors. In each instance, the creatures help spotlight the hundreds of humbler but equally endangered species: the black-spored quillwort, the longhorn fairy shrimp.”
—”Birth and Rebirth,” USA Today, August 23, 1999

Usually thought of as poster children for environmental issues, they’re often super cuddly or super scary. Or both (like polar bears).

I’d add to this list:
Jellyfish (alien death squad)
Squirrels (mischievous urban representatives)

But people look at me funny if I start geeking out about plankton or mycelial networks (although the latter can get pretty trippy). If we could spin them right, they’d be seen for the superheroes they are.

More on the Uncharismatic Poster Children:

Mycelium Running:
How Mushrooms Can Help Save the World

and Paul Stamets’ talk from TED:

(Above: Mycologist Paul Stamets lists 6 ways the mycelium fungus can help save the universe: cleaning polluted soil, making insecticides, treating smallpox and even flu … LINK to Stamets’ web site fungi.com)

April 12, 2009April 13, 2009

Jellyfish/Plankton/Plastics tangle continues

Animals that eat jellyfish also eat plastic bags
Animals that eat plankton or fish eggs also eat plastic pellets
Animals that eat fish also eat plastic.

Nurdles, Before - During - After (phots from flickr) — Nurdles: Before - During - After (photos from flickr)

MSNBC posted a story on April 9, about leatherback turtles’ diet of plastic bags.

A new study looked at necropsy reports of more than 400 leatherbacks that have died since 1885 and found plastic in the digestive systems of more than a third of the animals.

Leatherback turtles are critically endangered and highly charismatic creatures. They are big, weighing 1,000 pounds or more, with shells that can measure more than 6 feet across. These peaceful creatures have had the same basic body plan for 150 million years.

Leatherbacks are also popular for what they eat: namely, large quantities of jellyfish. The problem is that plastic bags look a lot like jellyfish, and plastic often ends up in the oceans, piling up in areas where currents — and turtles — converge.

Plastic can block a turtle’s gut, causing bloating, interfering with digestion, and leading to a slow, painful death. “I can’t imagine it’s very comfortable,” he said. “Their guts weren’t designed to digest plastic.”

There are vast fields of trash floating in the world’s oceans, Sasso added. And leatherback turtles travel thousands of miles each year, giving them even more opportunities to come in contact with it.

“This is an animal that has survived many extinction events,” James said, “And now it’s got all these anthropogenic hazards to face.”

And there’ve been a spate of publications on the amount of plastic – both nurdles, which are plankton or fish-egg -sized industrial plastic pellets from manufacturing shopping bags, dollar-store articles, and construction material that ends up in the oceans, and consumer plastic (bottles, bags, buckets, etc), which breaks down into ever-smaller pieces but does not completely degrade. This stat is from 2001:

There is now six times more plastic debris in part of the North Pacific Ocean than zooplankton, the populous animal plankton that forms the base of the aquatic food chain.
– C. J. Moore, S. L. Moore, M. K. Leecaster and S. B. Weisberg (December 2001). “A Comparison of Plastic and Plankton in the North Pacific Central Gyre”, Marine Pollution Bulletin 42)

Granted this statistic has been rejected because it only reflects an analysis made in the Pacific Gyre, a confluence of currents and thus a concentration of the contents of what’s carried on them; but even so, the volume of plastics is not decreasing. Some solutions: don’t take plastic bags, get refillable canteens for water. Reconsider the purchase of synthetics which may discharge plastics on the manufacturing process. Consider what else you can do with the plastics you are about to throw in the garbage.

If fish are eating plastic nurdles, then so are we if we eat fish.

Here’s more nurdle info:
http://www.nurdlesaretheenemy.com/

http://theurbancoaster.com/index.php?option=com_content&view=article&id=179&Itemid=92&lang=en

http://ewasteguide.info/more-plastic-plankto

April 12, 2009April 12, 2009

Jellyfish Gone Wild

It’s spring break the oceans over.

Sign on beach in Australia. Credit: Dr. Jamie Seymour, James Cook University

Australia’s beaches regularly host many types of toxic gelatinous animals, including the notorious Portuguese Man-of-War and Chironex fleckeri, a type of box jellyfish that is the world’s most venomous animal; a Chironex can kill a person in under three minutes.

In addition, some species of potentially deadly box jellyfish known as Irukandji jellyfish are currently increasing in number in Australian waters, possibly because of climate change. These peanut-sized jellyfish are small enough to slip through nets that protect Australia’s beaches from their larger Chironex cousins.
–The National Science Foundation

The National Science Foundation has published an extensive report on the Dead Zone/jellyfish connections, but I thought I’d quote the article’s description of the upsides of jellyfish:

ECOLOGICAL ROLES OF JELLYFISH

Plying the world’s oceans for over 500 million years, gelatinous creatures have influenced marine communities almost as long as marine communities have existed.

As prey, gelatinous creatures are eaten by seabirds, pink salmon, sun fish, turtles and other gelatinous creatures. (Animals that eat jellyfish are not impacted by their stings.) As predators, gelatinous creatures eat fish eggs and larvae, invertebrates, small, floating creatures called zooplankton and other gelatinous creatures.

Scientists are continuing to identify new ecological services provided by jellyfish. For example, recent studies show that the tentacles dangling from the Bering Sea’s large jellyfish provide hiding places for young pollock that are pursued by other predators but have grown too big for the jellyfish to eat.

…This last upside, while über poetic (Jellyfish-as-beaded-curtain; Quick! let’s duck out of harm’s way and hide in this undulating petticoat) does make me wonder if the upsides are outweighed by an anvil-load of problems.