Hawksbill Sea Turtles: endangered species discovered in Pacific mangroves

Sea turtles, collectively, are some of the most endangered animals in the sea, due to loss of habitat, illegal poaching for the turtles and their eggs, and as accidental bycatch. The hawksbill sea turtle is no exception and, in fact, is listed by the World Conservation Union as critically endangered and CITES prohibits the capture and trade of hawksbill trutles and any products derived from them.

However, such proclamations of status and prohibitions have not yet prompted the hawksbill turtle populations to recover. Even in the best of natural circumstances, sea turtle eggs and young hatchlings face formidable challenges that thins the population so just the hardiest, smartest, and luckiest survive.

Found throughout all oceans, primarily in warmer climates, hawksbill sea turtles often live among the corals reefs in the Caribbean and Indo-Pacific. By 2007, the eastern Pacific population of hawksbills were considered effectively wiped out. However, recent tracking studies lead by Conservation International has shown that the eastern Pacific variety of hawksbill may have found another habitat to call its home: saltwater mangroves.

The study, recently published in Biology Letters, reports, "New satellite tracking data on female hawksbills from several countries in the eastern Pacific revealed previously undocumented behaviour for adults of the species. In contrast to patterns of habitat use exhibited by their Caribbean and Indo-Pacific counterparts, eastern Pacific hawksbills generally occupied inshore estuaries, wherein they had strong associations with mangrove saltwater forests. The use of inshore habitats and affinities with mangrove saltwater forests presents a previously unknown life-history paradigm for adult hawksbill turtles and suggests a potentially unique evolutionary trajectory for the species."

It's not clear as to whether the hawksbill migrated from more open water environments to the mangroves - perhaps as a defense reaction to a declining habitat - or whether the eastern Pacific hawksbill had, by some evolutionary quirk eons ago, found the mangroves to be a suitable home along with coral reefs. But it does add one more reason for preserving mangrove ecosystems which are currently losing ground to coastal development and pollution.

Today, every species of sea turtle is threatened with extinction to one degree or another; as yet, none are in the clear. There are several organizations - Conservation International, PRETOMA, Turtle Island Restoration Network, and others - who are working to preserve and protect sea turtles and the environments within which they thrive.

Preserving Coastal Ecosystems: study shows loss of mangroves and salt marshes releases long-stored CO2

Surfbird News reports on all things related to coastal surfbirds and the environments that support them. The site recently reported on the findings of an international consortium of scientists on the impact on CO2 sequestration with the loss of coastal ecosystems like mangroves and marshlands.

Urgent Action Needed To Halt Increasing Carbon Emissions from Destroyed, Degraded Coastal Marine Ecosystems

The destruction of coastal carbon ecosystems, such as mangroves, seagrasses and tidal marshes, is leading to rapid and long-lasting emissions of CO2 into the ocean and atmosphere, according to 32 of the world’s leading marine scientists.

That key conclusion highlights a series of warnings and recommendations developed by the new International Working Group on Coastal “Blue” Carbon, which convened its first meeting in Paris last month. The Working Group was created as an initial step in advancing the scientific, management and policy goals of the Blue Carbon Initiative, whose founding members include Conservation International (CI), the International Union for Conservation of Nature (IUCN), and the Intergovernmental Oceanographic Commission (IOC) of UNESCO.

Much of the carbon emitted when mangroves, seagrasses or tidal marshes are destroyed is estimated to be thousands of years old because the CO2 stored in these ecosystems is found not only in the plants, but in layer upon layer of soil underneath. Total carbon deposits per square kilometer in these coastal systems may be up to five times the carbon stored in tropical forests, due to their ability to absorb, or sequester, carbon at rates up to 50 times those of the same area of tropical forest. The management of coastal ecosystems can supplement efforts to reduce emissions from tropical forest degradation.

Dr. Emily Pidgeon, Marine Climate Change Director at Conservation International, and a leading blue carbon conservation scientist emphasized, “We have known for some time the importance of coastal ecosystems for fisheries and for coastal protection from storms and tsunamis. We are now learning that, if destroyed or degraded, these coastal ecosystems become major emitters of CO2 for years after the plants are removed. In the simplest terms, it’s like a long slow bleed that is difficult to clot. So we need to urgently halt the loss of these high carbon ecosystems, to slow the progression of climate change.”

“The capacity of coastal wetlands to reduce climate change by capturing and storing carbon dioxide is considerable, but has been overlooked” says Jerker Tamelander, Oceans and Climate Change Manager for IUCN. “If valued and managed properly, coastal ecosystems can help many countries meet their mitigation targets, while supporting adaptation in vulnerable coastal areas.”

Read the entire article in Surfbird News.

Mangroves: new study shows less than previously estimated of critical shoreline forest

With the recent Gulf Oil Spill disaster, the subject of mangroves has become a hot topic. We have all seen the images of oil lapping at the roots of mangroves in Louisiana and Florida, choking the life that not only is growing from the silty bottom on up, but which also surrounds the mangroves in the form of shrimp, sea larvae, and newly hatched fish seeking protection.

Now, a new study published in Global Ecology and Biogeography warns that the world's entire acreage of mangroves has been overestimated, that there is less than originally thought and that we are losing these critically important aquatic forests at an alarming rate.

Scientists from the United States, Australia, and Kenya poured over the most recent satellite data taken by the U.S. Geological Survey for its Global Land Survey, along with other archive images, that utilize remarkable high resolution Landsat satellite photographs. By comparing them to previous estimates by the United Nation's Food and Agriculture Organization (FAO), it was found that overall, mangrove forests are 12.9% less than previously thought. And since 1980, 20% to 30% has been lost globally, with mangrove forests disappearing at an average rate of 1% per year.

As reported by BBC Earth News, Dr. Chandra Giri, one of the scientists involved in the study, warned, "13% is significant, especially as it is disappearing faster than inland tropical forests. We need to preserve the remaining mangrove forests with urgency otherwise they might disappear."

What makes mangroves so important? First, they serve as a protective nursery for a variety of sea life. Their root structures and the action of the roots on the fine ocean sediment make for ideal habitat conditions for oysters, sponges, algae, shrimp, lobsters and other small crustaceans - not to mention offering a safe haven for a variety of larval and juvenile fish. The loss of mangroves as nurseries can have a profound impact on adult populations further out at sea.

Because of the mangroves' massive root networks, they also serve to protect fragile coastlines from erosion. The impact of daily tidal ebb and flow - and even the extreme action of storm surge or tsunami movements - are moderated by this botanical line of defense. And the mangroves can assist in filtering and maintaining water and air quality by sequestering CO2 and helping the sediments to retain gases and heavy metals.

While the Gulf of Mexico's mangroves have received a lot of publicity of late, 40% of the world's mangroves are located in Asia (compared to North and Central America's 15%). Often based at the mouths of large delta river areas, the shrinking mangrove forests pose a major risk to local communities both from heightened exposure to the elements and from the negative impact on seafood that is a means of economic or nutritional survival.

Read an abstract of the research study.
Read more about the study in Earth News.

Conserving The Crocs: Columbia's proactive approach with villagers to protect threatened reptile

I was watching a re-run of the PBS program series, Nature, and there was an interesting episode on monster crocodiles. The researcher was traveling the world in search of 20-foot+ crocs, most of which having been hunted over decades either as trophies, for their hides, or in defense of cattle and, in some cases, local villagers. The net effect was that these super-size reptiles were becoming a rarity, if not all together extinct.

Then today I read an interesting follow-up on the Conservation International (CI) web site. CI has been involved in working with government officials in Columbia and members of the IUCN in getting local villagers to help conserve remaining populations of American crocodiles that inhabit Columbian wetlands and mangroves. Although illegal to catch, subsistence-level villagers are enticed to catch crocodiles and sell them on the black market.

"Within the mangrove wetlands, the crocodile is an important umbrella species which helps to sustain the functioning of the ecosystem; among other benefits, crocodiles often eat dead fish, keeping the water clean for the other species that rely on it – including humans."

With the new government-sponsored approach, by locating crocodile egg nests, retrieving the eggs, incubating and raising them in a hatchery for the first year or so, then releasing them later into the wild, the hunters-turned-conservationists are improving the odds for the survival of the crocodiles, compared to how their dwindling numbers would survive on their own. Maintaining a healthier balance in the wetland/mangrove ecosystem means allowing nature's predators and scavengers to thrive, producing a stronger and healthier population of fish and better water quality - which benefits both the ecosystem and man.

Much like what happens when sharks are protected, rather than hunted, in reef areas, local villagers benefit from a healthier ecosystem that is a food source and there is also the ancillary economic benefit derived from ecotourism - crocodile tours have sprung up in Columbia.

Once again, protecting the environment pays off in more ways than one.

Read the entire Conservation International article.