Red King Crab

This is an interesting invasive species case. Red king crab, normally found in the Pacific Ocean, was brought into Norway’s seas by scientists in hopes of establishing a population for fishing in the 1960s and 1970s. In 2009, there were more than 2 million adult red king crabs found in this area.

The red king crab is destroying the ecosystem in the Varanger area, though. The scientists that introduced it did not realize how drastic this crab species could alter its environment. Not only do the crabs prey on larger individual organisms, but they also dig and scoop up the sediments looking for soft-bodied organisms to eat. Therefore, other species are being directly preyed upon, and the benthic zone is subject to destruction by these crabs.

location of the Voranger area

The article reports the decrease in numbers for other species. Specifically, more sedimentary species, such as echinoderms and large mollusks, decreased drastically in numbers. Because each species has a role in this ecosystem, their decrease is devastating. For example, some organisms’ function, like water pumping, helps maintain a healthy level of oxygen in the benthic zone. So because the crab is harming other species, the ecosystem as a whole is also being harmed.

The authors note that research on this species is vital as it can spread to other areas. Also, the affects of the red king crab are not fully studied. But, conservation ecology is a crisis science, as we learned in the first few lectures, so it is hard to decide how much time we should spend studying the crabs before we decide to take action, if at all.

But even if scientists decided on an exit plan for the red king crab from this area, would the local human population be okay with that? Now this is a commercial crab, with the government regulating its fishing. In 2009, quotas were set for 1,300 tons! How can scientists get people on their side if their economy is going to be hurt by saving the environment? Can another industry be developed by restoring the ecosystem?

The second article I listed studies the effects of loss of limbs on crabs. They found that if males lose their chelipeds (pincers), they cannot successfully mate with females. Males need to hold the females up, and without these appendages, they cannot reproduce. Also, if any crab loses its main appendages, it cannot feed as well, thus lowering its survival rate. As I read this article, I just imagined people picking off the claws of crabs as a way of decreasing the population size, which seemed silly to me.

From these two articles, the only way of removing these crabs semi-reasonably is by overfishing, in my opinion. But will the Norwegians be okay with that? And will the ecosystem return to what it was?

Oug, E., Cochrane, S. K. J., Sundet, J. H., Norling, K., & Nilsson, H. C. (2010). Effects of the invasive red king crab (paralithodes camtschaticus) on soft-bottom fauna in varangerfjorden, northern norway . Marine Biodiversity under Change, 41(3), 467-479.

Dvoretsky, A. G., & Dvoretsky, V. G. (2009). limb autotomy patterns in paralithodes camtschaticus (tilesius, 1815), an invasive crab, in the coastal barents sea. Journal of experimental marine biology and ecology, 377(1), 20-27.

Images found on Wikipedia.

Cetaceans in brackish habitats.

The boundary between river and ocean is a closely linked to human development. Rivers have long been used for transportation to inland areas and many ports/harbours today are situated in the mouth of a river. These dense forms of development on a limited ecosystem can severely affect the species which reside in this niche.

In a paper from 2002, Smith and Jefferson look at two cetacean species: the Irrawaddy River Dolphin and the Finless Porpoise, respectively classified as Endangered and Critically Endangered. Their intent was to collect information about their populations in order to determine what conservation actions should be taken in light of their findings.

The Irrawaddy River dolphin’s (see below) range spans from the coastlines in the Bay of Bengal, south-east Asia to the Java Sea, and Northern Australia to Papua New Guinea. However, within this range, a large percentage of the population resides in the waters off of Bangladesh. This main population is considered to be vulnerable, while the spread out, smaller sub-populations are critically endangered.

The Finless Porpoise (see below) population spreads even further, however it remains closer to the coast line as it prefers shallower waters; spanning from the coasts of the Persian Gulf, all the way to Japan. This species also has a few isolated populations in rivers, such as the Yangtze River in China (not to be confused with the actual Yangtze River Dolphin which is a different species altogether and considered to be functionally extinct even though it is only listed as critically endangered), which are classified as endangered, while their coastal counterparts are classified as threatened.

Both the Irrawaddy River Dolphin and the Finless Porpoise are threatened by pollution due to the nature of their habitat. Rivers carry pollutants downstream, creating high concentrations at the river mouth. Pollutants such as organochlorides bioaccumulate and the concentrations found in both brackish species have been reported as very high.

Another threat to these species is that because of their ability to survive in fresh water, they are sought out by dolphinariums due to the fact that it is cheaper to have a fresh water tank than a salt water one. Their proximity to the coast and their slow movement also makes them easier targets for capture. And, of course, the fact that they’re very friendly doesn’t hurt. There are reports of the Irrawaddy River Dolphin helping herd fish into fisherman’s nets in the Ayeyarwady River Basin off the coast of Myanmar!

Overall the main threats posed to the Irrawaddy River Dolphin and the Finless Porpoise is habitat degradation and entanglement in coastal fishing nets.

ž AP. Study: Bangladesh hosts 6,000 rare dolphins. 01 April 2009. 13 October 2011 .

ž Smith, B D and T A Jefferson. “Status and conservation of facultative freshwater cetaceans in Asia.” Raffles Bulletin of Zoology (2002): 173-187.

ž http://en.wikipedia.org/wiki/Finless_porpoise

ž http://en.wikipedia.org/wiki/Irrawaddy_dolphin

Proposed Road through The Serengeti

In 2010, it was proposed to construct a road that would pass through the Serengeti National Park (shown in red on the map). Its purpose was to make travel easier through eastern Tanzania and the central African nations. However, the road would go directly through the middle of a migration path that about two million animals depend on, including wildebeests. In addition, the road would cut through a large portion of other habitats throughout the Serengeti National Park.

This proposed road would have many implications for the wildlife of the area. The most obvious problem is the potential for migrating animals to get hit by the traffic that is now passing through their habitat. Even worse, the road may stop the ability of the animals to migrate successfully and force them to find other refuge. Not only would the road affect the migration pattern, but the Serengeti National Park could also suffer the effects of habitat fragmentation.

As of right now, the plans for the road have been discontinued, but it is possible that the construction of this road will be brought up again for debate at a later date. What other consequences could the Serengeti National Park face if these plans were put to action in the future? Would the large scale migrations be possible with this overwhelming obstacle?

L. Dollar. (2011, June 24). Is the Serengeti Highway Really Cancelled? [Scientific blog post]. Retrieved from http://newswatch.nationalgeographic.com/2011/06/24/is- serengeti-highway- really-cancelled/.

S. Pimm. (2010, June 18). The Serengeti road to disaster. [Scientific blog post]. Retrieved from http://newswatch.nationalgeographic.com/2010/06/18/serengeti_road/.

Alex Cohen

Mmm, that aquacultured fish sure is tasty!

Have you ever wondered where the fish you ate came from? Or especially the raw sushi you ordered from Sushiya? It’s not a bad question to ask yourself, as studies determined that about half of the world’s consumed seafood is manufactured. So how authentic, really, is that salmon you had for dinner last night?

The farming of fish and sea creatures under controlled conditions—referred to as aquaculture—is one of the fastest growing areas of animal food production, growing at the rate of 8.4% since 1970. It provides a sustainable source of food supply, which would be great to help bridge the gap between food demand and availability. And how high is that demand you ask? Studies by the Food and Agricultural Organization determined that each person consumed an average of almost 17 kilograms of fish last year! With the exponentially growing human population that will presumably soon take over the Earth, that is a whole lot of fish! Sadly, it turns out that even the tremendous depths of the oceans have limits. According to a Times article on aquaculture written by Bryan Walsh, “the U.N. reports that 32% of global fish stocks are overexploited or depleted and as much as 90% of large species like tuna and marlin have been fished out in the past half-century.” This is where aquaculture steps in with high hopes of fulfilling our seafood-eating desires, while hopefully straying away from emptying our vast oceans of these beloved creatures.

But with every solution comes a multitude of problems, unfortunately. Environmental costs that arise from aquaculture are major concerns that worry ecologists. Disease is easily spreadable amongst the fish since they are so densely packed in ponds and tanks, and the destruction of forests to make room for these sea creature farms is preposterous. Another big issue is that in order to manufacture 1 lb of fish, it requires 2 lbs of ground wild fish as food, therefore creating a net ocean loss. However, humans are smart beings and often come up with solutions to override problems. Biologist Thierry Chopin proposed his integrated multitrophic aquaculture (IMTA) plan to build an aquacultural system that mimics nature. That way, the waste produced by fish wouldn’t pile up and can be used by other organisms such as seaweed, which in turn provides food for the fish. And a solution for the 2 lbs wild fish for every 1 lb farmed fish? Farm tilapia and barramundi instead of salmon because the prior are vegetarians and the latter are flexible in every which way: in terms of diet and living environment.

The production efficiencies of sea animals is beneficial in providing our bodies with protein and satisfying our pallets, but it is also less environmentally damaging than terrestrial agriculture such as beef and pork production. Cultivating fish requires less feed than raising livestock, and since fish are cold-blooded, less energy is wasted to keep them warm.

The role aquaculture plays in saving and preserving wild populations of fish may make it one of conservative ecology’s most prized ocean-saving possessions—if performed in an efficient manner with respects to providing us healthy food, while also making sure to reduce the environmental impacts. Although it doesn’t necessarily cause the ocean dwellers to reproduce and exponentially increase their population like us humans do, it does help to prevent them from being so greatly depleted. That is, if we farm tilapia and barramundi, as opposed to salmon and cod. Now if only we can come up with solutions for our other oceanic problems such as acidification, so that our coral reefs would look spectacular once again and we can all live in utopia…

Sources:

Sabto, Michele. “Managing Aquaculture’s Net Benefits.” Ecosmagazine.com. ECOS Towards a Sustainable Future, 8 Aug 2011. Web. 12 Oct 2011.

Walsh, Bryan. “The End of the Line.” Time.com. Time Science, 7 Jul 2011. Web. 12 Oct 2011.

Westlake, Louise. “Tasting the Future of Farmed Seafood.” CNN.com. CNN World, 25 Mar 2011. Web. 10 Oct 2011.

No dogs allowed? Is there scientific reason for that?? Allowing our furry buddies in America’s national parks.

Have you ever wanted to bring your sweet little dog on a road or camping trip, to only have the man bring you down with his regulations? Your canine pal may have less to do with lower species abundance and richness in America’s protected areas than you do.

In a study by Reed and Merenlender, human activities in the protected areas of California are actually the principle cause of these of native carnivore disturbance, rather than their dogs. Regulations are in place such that dogs are to be restricted in our national protected areas for fear that they might be vectors for disease, predation, or competition. They compared three different types of parks that allowed dogs on leash, off leash, or were not allowed.

When compared with each other, it was found that no matter which regulations were in place, there was no effect of dog presence/absence on the native carnivore populations. What was found was that in areas that excluded all human activity no matter how minimal the activity was, the native carnivores were much more effective and diverse. This was due to native predators general avoidance of cleared areas such as roads, campsites, and well-used trails.

So, when deciding what laws should be enforced regarding land use, we should not be discriminatory to our four-legged fidos. We less cute humans should accept that our activities are responsible for any decline in native faunal function not just pin it on certain behaviors of pets. Dogs are just along for the ride; we have the power to create areas that can be more accommodating to native fauna, as well as Scooby.

REED, S. E. and MERENLENDER, A. M. (2011), Effects of Management of Domestic Dogs and Recreation on Carnivores in Protected Areas in Northern California. Conservation Biology, 25: 504–513. doi: 10.1111/j.1523-1739.2010.01641.x

Davis Toad Tunnel

The Daily Show With Jon Stewart	Mon - Thurs 11p / 10c
Colbert - Tunnel Vision
www.thedailyshow.com
Daily Show Full Episodes Political Humor & Satire Blog The Daily Show on Facebook

The Environmental Crisis Finds Religion

Here are the book reviews that I mentioned in class last week "The Environmental Crisis Finds Religion". Also, here is a link to an old post that I made concerning a world summit on Religion, Science, and the Environment that may be of interest.

Also, there is a working group dedicated to Religion and Conservation Biology within the Society for Conservation Biology.

As we read in Ehrlich's piece last week "scientific analysis points toward the need for a quasi-religious transformation of contemporary cultures." If anyone has any evidence of these scientific analyses or any record of this transformation taking place, feel free to add your comments here!

A Completely Strange, Highly Endangered Mammal

For those of you interested in large mammal conservation and the possibility of bringing back species from incredibly small populations, here is a particular species of interest. It is a good example of how large megafauna can receive a lot of attention and be brought back from the brink. For good or ill, I think such a bizarre lineage deserves saving. As a side note, this blog is an incredible resource for anyone interested in zoology/evolution of terrestrial vertebrates. Be sure to check out the older versions on ScienceBlogs and Blogspot.

The Tasmanian Devil's Dilemma

Because I couldn't resist an excuse to take a break from schoolwork to go look at lots of pictures of Tasmanian devils...

The Tasmanian devil went from being a populous species to being an endangered one within the course of a little over a decade (1996 to the present), being declared endangered in May of 2009. Unlike many other cases, the cause of this is not human activity; it is disease.

Tasmanian devils (simply called ‘devils’ in the literature—who says scientists don’t have a sense of humor?) are the largest extant carnivorous marsupials since the thylacine went extinct in the twentieth century. They are, as their name suggests, native to Tasmania. They are also adorable. Before 1996, devils were widespread and quite common, (despite extensive human effort) with an estimated population size of around 150,000.

In 1996, a devil with facial tumors was photographed around Mt. Williams, Tasmania. During the next five years, numerous devils were observed to have similar tumors, and the population declined dramatically. Studies revealed that the cause of these tumors was an infectious cancer, quickly dubbed Devil Facial Tumor Disease (or DFTD). Infectious cancers are odd but do exist; the two other documented cancers of this sort affect dog genitals and inbred hamsters, respectively. Only the cancer affecting dog genitalia is known in the wild.

DFTD is invariably fatal. The cancer is transmitted when an infected devil bites another, more or less injecting cancer cells from its own mouth into the face of the other devil. Tumors soon develop. Though the cancer metastasizes rapidly, this is not the cause of fatalities; the facial tumors themselves are so large and painful that the animal soon is unable to eat and starves to death. There is no immunity within the devil population.

Since Tasmanian devils' courtship involves rather a lot of biting, the spread of DFTD has been rapid. Estimates of the species’ decline range up to 70% (O’Neill 2010). Indeed, the decline has been so dramatic that it has begun to affect the age at which females are breeding; the usual age before the advent of the disease was about 2 years, (with an expected lifespan of 6 years), but now, females have been observed breeding as young as 1 year of age. The rapid progress of the disease means that few females survive more than one breeding season.

DFTD is not the only problem the devils have to deal with. Aside from human activity, Tasmania has a problem with invasive red foxes, which prey upon smaller marsupials and compete with the devils. They are also thought to predate on juvenile Tasmanian devils. It has been proposed that the large devil population prior to 1996 helped prevent fox invasion, and the rapid decline facilitated the current fox population explosion.

In an effort to control this, the Tasmanian government started an eradication program, putting out poisoned bait for the foxes. The only problem was that the Tasmanian devils seem to find the bait just as interesting as the foxes do. The current suggestion to remedy this problem is to bury the bait at a depth of 15 centimeters, but this only dissuades the devils; it is not a reliable solution.

Multiple efforts are ongoing to try to save the species. Isolating uninfected devils, captive breeding and even measures so drastic as culling infected individuals, and storing sperm from deceased individuals have all been suggested or are underway.

((For those of you who are curious as to what the effects of the disease look like, here’s Wikipedia’s page image. Warning: Not for the faint of heart. Or those thinking about eating in the near future. http://en.wikipedia.org/wiki/File:Tasmanian_Devil_Facial_Tumour_Disease.png))

Sources:

Hughes Channing; Gaffney Robbie; Dickman Christopher R. A Preliminary Study Assessing Risk to Tasmanian Devils From Poisoning for Red Foxes. Journal of Wildlife Management, volume 75, issue 2, pages 285-392, February 2011

Keely, T; McGeevy, P.D.; J. K. O’Brien. Characterization and Short-Term Sperm Storage of Tasmanian Devil Sperm Collected Post-Mortem. Theriogenology, volume 76, issue 4, pages 705-714. September 2011.

Lachish Shelly; McCallum Hamish; Mann Dydee; et al. Evaluation of Selective Culling of Infected Individuals to Control the Tasmanian Facial Tumor Disease. Conservation biology, volume 24, issue 3. Pages 841-851, June 2010

McCallum, Hamish, Tasmanian devil facial tumour disease: lessons for conservation biology, Trends in Ecology & Evolution, volume 23, issue 11 pages: 631-637, November 2008

O’Neill, Iain D. Tasmanian Devil Facial Tumor Disease: Insights Into Reduced Tumor Surveillance From an Unusual Malignancy, International Journal of Cancer, volume 127, issue 7. Pages 1637–1642, October 2010

Lachish, Shelly; McCallum, Hamish; Jones, Menna. Demography, Disease and the Devil: Life-History Changes in a Disease-Affected Population of Tasmanian Devils (Sarcophilus harrisii), Journal of Animal Ecology, volume 78, issue 2 pages 427–436, March 2009

http://en.wikipedia.org/wiki/Devil_facial_tumour_disease

http://en.wikipedia.org/wiki/Tasmanian_devil ((I also nicked the image from here. Yay Wikipedia!))

Lost youth

By the time an American child is 3 years old, he or she can recognize, on average, 100 brands. Marketers are beginning to aggressively target products to the 0-3 age bracket.

From an article in Adweek: The Next Great American Consumer

This will be relevant later in the course but I thought the article was interesting, fairly shocking and, ultimately, rather depressing. 


I'm pretty sure I couldn't identify a single brand when I was 3, although I'm constantly reminded of the power of the messages that I did learn at a young age. You never lose them. The thought that advertisers are tapping into this susceptible and very vulnerable market is disturbing.