Thriving Oceans

A new publication in Conservation Biology is shedding light on the effect of a low population on fertility success in sea turtles.  And unlike other species that experience reduced fertility when population densities drop, green sea turtles, loggerhead sea turtles, and their conservationists are receiving a bit of good news. 

“We found that there has been no reduction in fertility in small nesting aggregations in either of these species worldwide.”

The well known issue of sea turtle overexploitation has sparked recovery efforts around the globe.  But the lingering question was whether some turtle populations have passed the point of no return and would thus be unable to ultimately avoid extinction.  According to researchers, marine species have had a variable success rate in recuperating from low numbers, which is a product of the biology of the species and human pressures like habitat degradation and harvesting.  However, these latest findings suggest that even populations comprised of very low densities have a chance at recovery (Previous critical density models indicated depensation might occur when populations dipped below 5% of historical numbers).

“Furthermore, there was clearly no pronounced reduction in fertility in either species at low numbers, even in rookeries yielding as few as 10 clutches per year.”

 

“The capacity to maintain functional levels of fertilization success in the face of high levels of exploitation may help in part to explain why total extirpations have been few and recoveries have been possible.  This information does not, however, explain why in some cases recovery has not occurred.”

I guess the biological moral of the story is that even highly reduced populations have an “intrinsic conservation value”, and can provide much needed information in sea turtle biology and aid in global recovery efforts.

BELL, C., BLUMENTHAL, J., BRODERICK, A., & GODLEY, B. (2009). Investigating Potential for Depensation in Marine Turtles: How Low Can You Go? Conservation Biology DOI: 10.1111/j.1523-1739.2009.01313.x

TODAY IS A GREAT DAY FOR SEA TURTLES!  Check out the following press release:

NASSAU, Bahamas — The Ministry of Agriculture and Marine Resources hereby announces that the Fisheries Regulations governing marine turtles have been amended to give full protection to all marine turtles found in Bahamian waters by prohibiting the harvesting, possession, purchase and sale of turtles, their parts and eggs. The new regulations also prohibits the molestation of marine turtle nests.

The regulations will come into effect on Tuesday, September 1st, 2009.

The Government has engaged in intensive and extensive consultations with the public over the issue of the ban on the harvesting and sale of marine turtles for the past twelve months. The commitment to the conservation and preservation of these species while in Bahamian waters has been demonstrated by the introduction of protective measures and safeguards over the past two decades, starting with the actions taken to safeguard the hawksbill turtle in 1986.

An eternity, perhaps not quite, but that’s my perception of time when thinking back to my Hawaiian excursion in mid-June.  And finishing up a home movie chronicling our adventure, complete with contemporary Island music from the likes IZ for instance, just gets me in the mood for some white sandy beaches and clear salty waters.  So why not share a few things I came across while swimming over the reefs of Maui.

Obviously such a post lends itself infinity as the amount of pictures and video I have is substantial… notice I did not mention anything about quality.  But with that said, using a digital underwater camera is  a goldmine for someone who needs to cull through the blurs to find a few gems. 

Of course I need to start the ball rolling with a Hawaiian green sea turtle.  It is by far my wife’s favorite marine creature and I am always left in awe at the range of colors found on their carapace.  By the way, did you see our Hawaiian green sea turtle video footage?  And even in today’s world of rampant conservation information,  I was left in shock to discover people clamoring to touch and harass this amazing species (And yes members of our party spoke up immediately to inform the culprits and end their activities). I guess that’s why we need to continue spreading the word.

Hawaiian Green Sea Turtle

A juvenile yellowtail coris (Coris gaimard), which is the first one I have run across in Hawaii

A raccoon butterflyfish (Chaetodon lunula)

A Slate or Red pencil urchin (Heterocentrotus mammillatus) and a black sea urchin (Echinothrix diadema)

A cushion seastar (Culcita novaeguineae)

Whitemouth moray eel (Gymnothorax meleagris)

An Arc-eye hawkfish (Paracirrhites arcatus)

The Hawaiian Day Octopus (Octopus cyanea) and a female bird wrasse (Gomphosus varius)

“It ain’t easy being endangered!”

Photo credit: NMFS