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Will Climate Change Alter Sea Turtle Populations to the Point of Extinction?

Posted by Scott A. On June - 15 - 2010

Our planet is an intriguing concoction of variables that meld together for successes spanning the organization of life (species, populations, communities, and ecosystems).  It is literally an evolutionary process that is ecologically driven.  And as a genotypic sex determined species, we seem to have an inherent fascination with the mysterious adaptive significance of environmental sex [...]

Proposal to save whales means lifting whaling ban and sanctuary harpooning

Posted by Scott A. On May - 28 - 2010

It’s probably not much of a limb to go out on, but I’m pretty sure there is a clear majority and mandate by Americans to halt whaling, let alone lend official support and endorse such actions by other nations.  And I think I may enter the frigid waters and tackle our own policies regarding indigenous [...]

Killing Sharks: Is Ocean Science Compatible with Ocean Conservation?

Posted by Scott A. On May - 12 - 2010

I’ll be perfectly honest…I’ve been sitting on this essay from Conservation Biology for the last week or so as I mulled over my approach on breaching this topic.  At one point I envisioned the title as Torn Between Ocean Science and Ocean Conservation; clearly a manifestation of the dilemma with which I was trying to [...]

Atlantic Bluefin Tuna: Conservation Thwarted by Profits

Posted by Scott A. On March - 18 - 2010

An organization that delegates [tries to] policy without any foreseeable recourse at their disposal is simply a Think Factory.  They ‘THINK’ they can get offenders to comply merely on the basis of suggestion.  Perhaps this tactic works in the world of science fiction when the wave of a Jedi’s hand is all that is needed [...]

Declining Parrotfish Instill Hope but Highlight Human Flaw

Posted by Scott A. On December - 1 - 2009

While rummaging through the latest research in Conservation Biology, I came across a publication that caught my attention.   It’s not that the title conveyed a trinket of enlightenment nor promised to do so as I wound my way from introduction to methods to discussion.  In fact, the title evoked an emotional response that was the [...]

sunOur planet is an intriguing concoction of variables that meld together for successes spanning the organization of life (species, populations, communities, and ecosystems).  It is literally an evolutionary process that is ecologically driven.  And as a genotypic sex determined species, we seem to have an inherent fascination with the mysterious adaptive significance of environmental sex determination.  But the evolution of environmental conditions, such as temperature, determining the sex of offspring is not what is going to be explored at this time.  Nor do I plan to open up a heated discussion about climate change.

However, I am curious about the population dynamics of species exhibiting temperature-dependent sex determination in a warming world.  More specifically, how will sea turtle populations fare if sex ratios are dramatically skewed as a result of warmer temperatures.  Yet worry not as I am not alone in wondering about the stability of our threatened and endangered sea turtles.

Scientists from the Institute of Life Science, Institute of Environmental Sustainability and the National Marine Park of Zakynthos executed a study to determine if “temperature-dependent sex determination increases the probability of extirpation when ambient temperatures induce the production of offspring of a single sex.”  Especially when, “Some taxonomic groups, such as sea turtles, are already endangered and have sex ratios skewed to the sex produced at warmer temperatures (females).”

However, measuring population viability is more than just determining the ratio of male and female hatchlings.  Species stability requires a measurement of the number of males and females that are ready to mate at any one particular time (operational sex ratio), which also accounts for the breeding frequencies of each sex.

Results:

  • Based on hatchling ratios, it is assumed that for every 100 adult turtles in the population, there were 70 females and 30 males.
  • Males return to breed every year
  • Females breed every 2.6 years
  • Operational sex ratio is 47% female – in any particular year 30 out of 30 males will be breeding, but only 27 out of 70 females will breed.

baby loggerheadsSo just what does this data all mean?  Well, the most striking finding is that since male sea turtles breed more frequently than females (i.e. an operational sex ratio that is not female biased), they are able to “reduce the probability of unfertilized clutches.”  Even though males already comprise a smaller portion of the population, and would do so to a greater extent in a warming climate, the results are indicating that we (or they) do not have much to worry about when it comes to temperatures altering the sex ratios to a point where the population collapses.  But perhaps this just might be limited to the SHORT-TERM.

As pointed out by the authors, a male breeding cycle that is 2.6 times greater than females may help alleviate the impacts of climate change on the population, but there will undoubtedly be a reduction in males over time.  And as males become limited the probability that a population will persist declines.

For example, it is predicted that under some climate-change scenarios, nesting beaches in some parts of the world will produce only female hatchlings.  If this hatchling sex ratio propagates into adult sex ratios (e.g., there is no immigration of males from other sites), then the increased breeding frequency of males will be redundant because there will be no males.

Thus, we just may find ourselves taking on the role of the Earth’s climate by relying upon methods to control nest/embryonic temperatures in an attempt to artificially produce male hatchlings and ultimately prevent the loss of sea turtles.

ResearchBlogging.org
HAYS, G., FOSSETTE, S., KATSELIDIS, K., SCHOFIELD, G., & GRAVENOR, M. (2010). Breeding Periodicity for Male Sea Turtles, Operational Sex Ratios, and Implications in the Face of Climate Change Conservation Biology DOI: 10.1111/j.1523-1739.2010.01531.x

World Oceans Day 2010

Posted by Scott A. On June - 8 - 20101 COMMENT

It’s absolutely appalling that I do not have something pithy or uplifting prepared for World Oceans Day 2010.  Perhaps a scathing attack on the comedy of errors that has been allowed to continue in the gulf would be a nice addition considering today is a celebration of our planet’s oceans.  But even that is conspicuously absent due to my recent schedule.  However, I just couldn’t let the day slip by so I’ll let Oceana speak from the pulpit on my behalf.  And let’s work together to get ocean responsible.

Oh and one more thing…FIX THE DAMN LEAK!  Quit with the television propaganda and just do it!

Full of Life Those Anchialine Ponds

Posted by Scott A. On June - 1 - 20101 COMMENT

redshrimpEver heard of an Anchialine (‘near the sea’) Pond ? Well neither had I until I stumbled upon a series of these pools adorning the coast of the Big Island of Hawaii.  While following the convex nature of the coastline from Waiulua Bay to Anaehoomalu Bay, my eyes managed to wander from the crashing waves just in time to catch a placard telling passersby to refrain from disturbing sensitive habitat.  Of course I was curious and so I left the coral beach, stepped onto the tree-shaded dirt path and peered across lava beds that were cupping crystal clear waters.  But that is an understatement as far as  a description goes because the waters bristled with life, colorful algae coated the water covered rocks and birds waded in the waters and disappeared behind once molten rock.

I was really anxious to get a closer look and for a split second even contemplated a quick inspection, but that sign flickered in my head and I knew I had to keep a responsible distance; practice what I preach whether I liked it or not.  But it did not take long to discern a path made for human travelers had been installed and provided ample space for observation.  This was virgin territory, for me anyways, and I quickly managed to forget all the signs that indicated people had come and gone before…my expedition was underway.   I traversed the well groomed path and wondered whether they were fresh or salt or brackish water ponds.  I had hypotheses for each scenario, which was extended to include a reason for the presence of an incredible amount of small fish schooling in the variety of pools ranging from the scientific units of very small to quite large.  But I began to realize their salty nature after spotting the presence of a small surgeonfish swimming amongst the other gilled residents.  Besides fish, the ponds are home for algae, plants, shrimp, snails, insects and provide foraging sites for birds.

Alas, a sign describing yet another Hawaiian treasure identified the name of my latest discovery.  And before I provide additional verbiage and photos, I should mention that I was brought back to reality as the path ultimately ended amongst the streets of civilization. An adventure none the less.

“Anchialine ponds are one of Hawaii’s most threatened ecosystems. There are about 700 known anchialine ponds in Hawai’i. Most Hawaiian anchialine ponds are in the youngest lava areas of the Big Island of Hawai’i and Maui. They exist in inland lava depressions near the shore and contain brackish (a mixture of freshwater and saltwater) water. Freshwater is fed to the ponds from ground water that moves down slope and from rainwater. Ocean water seeps into the ponds through underground crevices in the surrounding lava rock.”  University of Hawaii at Hilo

According to the signs on site, “Tiny red shrimp, collectively called ‘Opae’ula, are one of the unique features of these anchialine pools and are found only in Hawaii.  The shrimp are omnivorous and can live for long periods of time underground in the interstitial groundwater without appearing in the pools.  The shrimp have been found in wells located a mile inland.  The smaller and more numerous shrimp (Halocaridina rubra) is preyed upon by a larger red shrimp (Matabetaeus lohena).”

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Humpback whale tailIt’s probably not much of a limb to go out on, but I’m pretty sure there is a clear majority and mandate by Americans to halt whaling, let alone lend official support and endorse such actions by other nations.  And I think I may enter the frigid waters and tackle our own policies regarding indigenous harvesting in another setting.  For now, I like to imagine that the approval rating for whaling is somewhere in the single digit range, but after reality sets in I doubt we have yet to reach the incredible homogeneity that the populace of Australia has been demonstrating.  As reported by Time, ” A national poll conducted in January [2010], 94% of Australians said they were against whaling.”

As for the U.S., the numbers I have on hand are two decades old, but it does speak to our disdain for a practice that seems only fitting for 160 year old novels and blurry monochromatic photos adorning museum walls. The poll found that 83 percent of American voters oppose killing whales, 61% “strongly” oppose whaling, 82 percent want government officials to speak out publicly against commercial whaling, and 55% believe the U.S. government should impose limited trade sanctions banning the import of seafood products from countries that continue whaling (Schoen & Berland Associates 1999).

Now that a new proposal to lift the ban on commercial whaling is making headlines, I am wondering if the voices of the American people are simply being ignored…again.  And I think there really might be a disconnect between governments, the International Whaling Commission, and the people when it comes to this particular issue.  WHALES ARE NOT ANIMALS.  And I think most of us inherently understand this ideology and have a connection to cetaceans that far surpasses something that can simply be chalked up to the love for a high profile, charismatic species.

So for those wondering what whales are if not simply animals, the answer is a BEING.  We are human beings and they are whale beings; it’s an existential connection based on mutual respect, based on intelligence, and based on the fact that we see us in them.  Yet it is so much more than mere anthropomorphism as I/we embrace them as colleagues in life.  Thus, many of us perceive whaling as an antiquated notion, whether or not done under the guise of scientific permits.

Now that we have established a background, it’s time to circle back to the proposal to end a ban on whaling.  In March 2010, the International Whaling Commission (IWC) produced a draft proposal to address:

…the problems within the Convention; conservation and sustainability; healthy whale populations; exploitation and protection; whaling under special permit (‘scientific whaling’); small type coastal whaling; benefits for developing countries; monitoring and accountability; sanctuaries; the commercial whaling moratorium; an interim period; governance mechanisms of the IWC; animal welfare; aboriginal subsistence whaling; international trade; reservations and objections; whale watching; bycatch and human impacts; small cetaceans; an acceptable “Package”.

whaling-iwcAddressing problems is always a good thing, right?  Well, after waving away the smoke we find that the proposal not only recommends whaling for members of the IWC who are currently killing whales to legally do so for the next 10 years, but that the Obama Administration is backing the plan (Which by the way was announced in a press release on Earth Day 2010).  Additionally, the key is an “acceptable package,” which can be argued as strictly no whaling,  and is currently tied to the fact “that whaling catch limits are largely still to be determined.”  It is because of this ambiguity in the draft proposal that the International Fund for the Welfare of Animals (IFAW) is looking for support and involvement. 

“The plan can mean not only reversing the current ban on whale hunting by Norway, Iceland, and Japan for the next ten years, but will allow whaling in the internationally recognized whale sanctuary around Antarctica.” IFAW 2010

 Thus, I caught up with Chris Cutter, IFAW spokesperson, to find out a little bit more about this developing situation as they fight to protect a species in which we have so much in common.

Thriving Oceans:  What is your main concern with the new proposal and the backing by the current Administration?

Chris Cutter: Our main issue is that the administration is saying definitively that this deal would save X numbers of whales. The issue is that the current proposal has “draft” numbers in it.

 You could take the administration at face value and say the “intention” is to reduce the numbers of whales killed, but it’s inaccurate to say that the proposal would save X amount of whales without any hard figures to back that up.

Thriving Oceans:  Are we potentially jumping the gun by criticizing a draft proposal?

Chris Cutter:You could flip that around and say it’s inaccurate for IFAW and other NGOs to criticize the plan for the same reasons. Without any numbers it is impossible to assess. Suffice it to say, given the history of the negotiations to date, the structure of the proposal itself, and the fact that all of the conservation benefits are based on dubious science, we’re skeptical.

 Thriving Oceans:  So we’re potentially hearing some environmental pandering as the Administration is claiming whales are going to be saved?

Chris Cutter:  The problem is that there will be hard numbers in the proposal when it is voted on next month. Until those numbers are written in ink, not pencil, no one should be talking about future numbers of whales killed or saved.

It is up to us to lead the effort in protecting these animals.

To learn about how you can get involved, please visit IFAW on Facebook or visit www.IFAW.org.

Amazing Cephalopods

Posted by Scott A. On May - 27 - 2010ADD COMMENTS

InterviewThere is never a dull moment when it comes to discussing wildlife and conservation and if you keep your eyes open there is always an opportunity to learn some great facts.  And perhaps a perk I never really envisioned when I began throwing words upon the web was networking.   I have forged many great relationships through JournOwl and Thriving Oceans and many more are burgeoning at this very instance.  And I am always on the lookout for innovative ways to spread the word and get people of all ages excited about the natural world.  It’s definitely a passion…and  just maybe teetering on the brink of obsession; in a good way of course.

Well, this leads me to my ultimate point about networking, new friendships, talking conservation, spreading a positive message and divulging a little history of where things all started and where things are headed in my ocean world.

So wander on over to Oceans 4Ever and check out my latest interview (How it all started for Scott Artis) with some enthusiastic, like-minded ocean conservationists.  And we also had a chance to talk about making a difference so don’t pass up…Kids & conservation – five easy things kids can do today to help oceans.

 What are we waiting for, Let’s Get Ocean Responsible!


    • Visit Thriving Oceans