Thriving Oceans

My sea turtle hazard is worse than your sea turtle hazard. 

Of course.  

Sounds logical. 

And more importantly it falls within that quirky social dynamic called HUMAN NATURE.  But the results of bias within the scientific community is an interesting topic; especially when you add the sea turtle variable and the number of threats plaguing the seven species.  So put any preconceived notions that you may have aside and let’s see if we can all come together and accept the fact that the hazard I’m researching poses the greatest threat to sea turtles.

Well, perhaps we should turn to the experts and listen to what they have to say.  And that’s exactly what the authors of a new publication, Using Expert Opinion Surveys to Rank Threats to Endangered Species: A Case Study with Sea Turtles, in Conservation Biology did.  And should we really be surprised by the findings?

An internet-based survey was distributed to sea turtle experts that was designed to determine the respondents’ overall experience, expertise and the proficiency in regards to particular species, geographic regions, and hazards.   Hazards that included pathogens, direct take, global warming, nest predation, pollution, coastal development, and fisheries bycatch.  After quantifying results spanning the nonprofit sector, government agencies, and respondents in over 100 counties, a pattern began to emerge.  A pattern attributed to expert bias.

“Respondents with no experience with respect to a sea turtle species tended to rank hazards affecting that species higher than respondents with experience.  A more-striking pattern was with hazard-based expertise: the more experience a respondent had with a specific hazard, the higher the respondent scored the impact of that hazard on sea turtle populations.” 

Perhaps a sign of the times, everyone was in agreement that sea turtles were under threat from multiple anthropogenic hazards.   It also became apparent that there was an overall consensus on the greatest hazard, fisheries bycatch.  The survey found:

• Bycatch was ranked as the top hazard for 18 sea turtle populations.
• Coastal development was ranked as the top hazard for six populations.
• Nest predation was the top hazard for three populations.

Interesting!  And I guess that exclamation warrants further development if I expect it to make any sense.  Although bycatch, a pelagic threat, ranked as a top hazard for 18 populations, a disparity still exists between coastal development and nest predation, which are terrestrial and coastal threats.  The amount of invested resources does not correspond to the highly scored pelagic threat. 

The authors point out that, “Twenty-eight percent of survey respondents reported conducting research or activities focused in the pelagic environment, compared with 70% who conducted research in both terrestrial and coastal environments.”

Which rounds off the discussion as to its applicability to conservation.  Should statistical methods that account for expert bias be implemented by conservation planning programs?  And should hazards that are both highly scored by experts and have a high uncertainty in regards to the range of effect on a population be treated as a research priority?

 Well one thing is for certain and I agree completely with the authors that, “Priority setting for the conservation of threatened and endangered species cannot wait for exhaustive empirical research.”

DONLAN, C., WINGFIELD, D., CROWDER, L., & WILCOX, C. (2010). Using Expert Opinion Surveys to Rank Threats to Endangered Species: A Case Study with Sea Turtles Conservation Biology DOI: 10.1111/j.1523-1739.2010.01541.x

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 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.

So 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.

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

It’s an article packed full of potential contention as it speaks to a variety of issues involving fisheries management.  So thank God we are dealing with a charismatic marine species or we just may be contemplating their extinction.  But then again, perhaps we are doing just that since all 7 species of marine turtles are listed under the Endangered Species Act.  So what does that mean when millions of sea  turtles are caught as bycatch in just 18 years?  I think it means the status quo is definitely due for an overhaul to say the least.

Bycatch.  It’s a word that sounds rather innocuous as it rolls off the tongue, but clearly does not do justice to the staggering amount of life that is instantly converted to simple biological waste.  It’s a problem that amounts to tonnes, in the neighborhood of several million per year.  And again I say thank God because the widely popular sea turtle may be able to help shine the light on an ever growing problem responsible for population declines in multiple species.  Well, at least I hope so.

In Global Patterns of Marine Turtle Bycatch, gillnets, longlines, and trawl fisheries are providing us with a perspective that we would probably rather ignore.  Unfortunately the out of sight out of mind attitude is not helping the sea turtle situation and it reminds me of an old mantra I used, “The catch of the day may cost more than you think.”  In this scenario, that cost is…

The total reported global marine turtle bycatch (1990-2008) was ∼85,000 turtles, but due to the small percentage of fishing effort observed and reported (typically <1% of total fleets), and to a global lack of bycatch information from small-scale fisheries, this likely underestimates the true total by at least two orders of magnitude.

And after looking at the data I am left wondering how many sea turtles are actually killed or die as a result of wounds incurred by coming into contact with gillnets, longlines and trawls.  I can imagine it is only palatable when wearing a pair of rose colored glasses.  But as far as the research goes, there was insufficient data to incorporate mortality rates.

The study found the bycatch per unit effort (BPUE) varied greatly depending upon the region and fishing method employed.  In fact , it identified certain hotspots that are a cause for concern and highlight the need for fisheries management intervention.

Based on reported sea turtle bycatch, the maximum BPUEs found for each fishing method are as follows:

• 2.2 turtles per set for gillnets in the Mediterranean Sea
• 19.3 turtles per 1,000 hooks for longlines in the eastern Pacific Ocean
• 7.2 turtles per haul for trawls in the southwest Atlantic Ocean

“Targeted action to reduce turtle-gear interactions is essential for population persistence, and is already underway for some fleets…our study revealed that reports of longline bycatch are two-fold more common than reports of bycatch in either trawls or gillnets.”

Having the data means we have no more excuses for not developing, continuing to develop and implementing a conservation plan that is both regional and fishing gear specific.  The plan must be more than focusing on turtle excluder devices, but must include other innovative management techniques on the lines of time-area closures, etc.  And since time is of the essence and marine turtle populations are at risk, immediate action is required.

Wallace, B., Lewison, R., McDonald, S., McDonald, R., Kot, C., Kelez, S., Bjorkland, R., Finkbeiner, E., Helmbrecht, S., & Crowder, L. (2010). Global patterns of marine turtle bycatch Conservation Letters DOI: 10.1111/j.1755-263X.2010.00105.x

Happy sea turtle Friday everyone!  Thought I’d send you off for the weekend with an encounter we had on the Big Island of Hawaii last week.  It must be the happening place for a slumber in the sun.  The photos are a little washed out as we were using our underwater camera, but if you look closely that’s a pile of 9 sea turtles.

A love for the ocean can be quite varied and in some instances inexplicable.  It is calming, extraordinary, deadly, mystical, full of life and truly deserves respect.  Honestly, I am not quite sure why I’m drawn to our marine ecosystems but my hypothesis is that it includes the previously mentioned adjectives as well as a hundred more that I could rattle off.  When you are hooked there is no turning back, ask any fish hobbyist; it’s an addiction.  And perhaps my first 10 gallon tank oh those many many years ago was the catalyst that sparked a lifelong love for all that is ocean.  Nirvana is breathing through a snorkel, watching fish, invertebrates, mammals, birds, reptiles and algae come together in perfect ecological balance.  I am an ocean lover!

I am also a conservationist, a biologist by training, and by default an anthropologist.  I look through the eyes of common sense, which is governed by conservation and biology.  And I watch and study people as they interact with the marine world; hence I delve into amateur anthropology.  Watching wildlife can be amazing, but watching people can be just as insightful.  With that I must conclude conservation is an interesting thing;  you never know how it will materialize but as for when it is every day.

A beer can left on the beach, a plastic bag allowed to blow into the waves or a parent that urges children to approach and prod a resting sea turtle are perfect opportunities to impart conservation ideals.  Which by the way can often be accomplished by simply setting a good example.  A beachcomber collecting debris that has washed ashore, a snorkeler collecting bottles and cans while swimming the reef, and an individual capitalizing on situations to educate the next generation are a few easy but worthwhile endeavors.

So just what is this all about?  Well a recent trip to the Big Island of Hawaii presented just such an opportunity as my wife and I wandered a beach along the Kohala coast.  We happened upon a green sea turtle that had pulled itself onto a beach made of lava rocks for a little rest in the morning sun.  As we captured a few snapshots from a distance (thanks to telephoto lenses!), a mother and her two children approached us and asked to see our sea turtle pictures.  After the exchange of a few words we pointed to the resting sea turtle…why look at pictures when actual observations can be made.  From a safe distance, the two girls watched the sleeping reptile as excitement filled their faces.  “Get closer,” the mother said softly, “it is OK as long as you don’t touch.”  As my wife and I exchanged glances the mother again urged the girls to get closer and closer.  After a moment of hesitation, the children heeded their mother’s wishes and were soon sitting next to the resting sea turtle. 

To be honest I was a little shocked at the request, but awe set in rather rapidly as the older child began using her plastic magnifying glass as an exploratory tool in lieu of her fingers.  Sidestepping the do not touch command on a technicality.  I understand the actions of the child and no doubt would have probably done the same at her age as such investigations are essential in learning.  But I was left waiting for the mother to step in and provide some guidance, a little lesson in wildlife respect, a explanation of threatened species, anything.  Although there was a lack of action by the parent, I could not bypass this incredible sea turtle encounter to make a positive learning experience, suggest a safe viewing distance, and hopefully spread a few cool sea turtle facts that she regurgitates while sharing her photos during show and tell.

It’s all in the attitude and one can often move conservation mountains by being non-confrontational, friendly and informative; especially when children are involved.  As I said, one never knows how an opportunity to teach marine conservation will present itself, but when it does just make sure you don’t miss the chance to set a good example.

Press Release from Sea Turtle Restoration Project  (Nov. 5, 2009)-

Sea turtle advocates in California and family shrimp fishers from Florida filed a federal lawsuit today against the U. S. State Department for violations of the Endangered Species Act (ESA) for allowing shrimp caught in ways that are deadly to sea turtles to be sold in the United States  The lawsuit filed by the Environmental Law Clinic at Stanford Law School (Palo Alto, CA) on behalf of Turtle Island Restoration Network (Forest Knolls, CA) and the Mayport Village Association (Mayport, FL) claims that the U. S. State Department has failed to properly evaluate and prevent harm to sea turtles from overseas shrimp fleets that sell shrimp to the United States under the ESA’s Turtle-Shrimp Law (Pub. L. 101-162 § 609). It was filed in the U. S. District Court, Northern District of California. See the complaint.

“This is not only a tragedy for sea turtles, which die by the tens of thousands in shrimp nets every year, but is unfair to the U.S. fishers who obey the law and must compete in the U.S. marketplace with shrimp imports,” said Todd Steiner, biologist and executive director of Turtle Island Restoration Network a non-profit organization dedicated to the conservation of sea turtles and their habitat.

“Our Mayport shrimpers are struggling to survive, while foreign fleets get a free pass on the law and flood the market with cheap shrimp,” said Al Millar, representing Mayport Village Civic Association and its small fleet of family shrimpers based in the historic village of Mayport, FL. See www.SaveMayportVillage.net. “We work hard to fish and protect sea turtles but don’t get a break from our own government.”

The lawsuit claims that the State Department has not properly enforced requirements for foreign shrimp vessels to use nets with Turtle Excluder Devices as U. S. fishers are required to do. The lawsuit asks that the foreign shrimp certification process be given additional environmental oversight and review. Recently, shrimp imports from Costa Rica were banned due to failure to protect sea turtles after environmentalists’ complaints, but 15 other nations were certified with little, if any, scrutiny.

“There is a simple, inexpensive, and elegant solution that allows sea turtles to escape drowning in shrimp nets, called a turtle excluder device or TED” said Deborah Sivas, Stanford Law professor, and director of the Environmental Law Clinic, who filed the lawsuit.  “If the State Department can create a reasonable certification program, we can save the lives of thousands of endangered sea turtles while allowing shrimp harvesting to continue.”

Americans consume over 500,000 tons of shrimp annually, and is the top fishery import of the United States, valued at over $3.9 billion last year, according to government figures. This includes trawl-caught wild shrimp and farmed shrimp (which does not capture sea turtles but is environmentally harmful due to pollution of fish ponds and land clearing). About 90 percent of shrimp eaten in the U. S. is imported. See latest U. S. shrimp import data.

Background:
The U. S. Turtle-Shrimp Law was challenged by nations at the World Trade Organization (WTO), claiming to be a violation of the “free-trade” agreement, leading to the famous “Battle of Seattle” protests in 1999 where thousands marched peacefully to protest weak environmental protections in the global trade treaty.  The U.S. Turtle-Shrimp Law was eventually found to comply with the WTO, but poor enforcement has allowed sea turtles around the world to drown in shrimp nets and slide toward extinction. (The movie Battle of Seattle starring Woody Harrelson that dramatized the protests was released in 2008). Read more .

On May 1, 2009, the Department of State certified, pursuant to Section 609 of Public Law 101-162 (”Section 609”), that 15 nations have adopted programs to reduce the incidental capture of sea turtles in their shrimp fisheries comparable to the program in effect in the United States. Belize, Colombia, Ecuador, El Salvador, Guatemala, Guyana, Honduras, Madagascar, Mexico, Nicaragua, Nigeria, Pakistan, Panama, Suriname, and Venezuela. The Department also certified that the fishing environments in 24 other countries and one economy, Hong Kong, do not pose a threat of the incidental taking of sea turtles protected under Section 609. Read more.