Good Pacific green turtle news


This 30 December 2018 video from Australia says about itself:

Tracking Green Turtles in the Great Barrier Reef | Fearless Adventures with Jack Randall

Jack dives into the Great Barrier Reef to wrangle Green Sea Turtles for wildlife conservation and study.

From PLOS:

Immense Pacific coral reef survey shows green sea turtle populations increasing

First comprehensive in-water survey shows key role of ocean temperature and human protection

April 24, 2019

Densities of endangered green turtles are increasing in Pacific coral reefs, according to the first comprehensive in-water survey of turtle populations in the Pacific. The study, by Sarah Becker of the Monterey Bay Aquarium in California and colleagues, publishes April 24 in the open-access journal PLOS ONE.

Coral-dwelling sea turtles have long been endangered due largely to human exploitation — hawksbills for tortoiseshell and green turtles for food — and destruction of coral reef habitat, but the institution of global protection efforts beginning in the 1970s aimed to reverse this decline. Land-based surveys of breeding and nesting sites have provided important evidence of population sizes, but are limited in scope and without confirmation from the ocean where the turtles spend the vast majority of their time.

To more fully understand the density of the populations of these two turtle species, as well as the environmental and anthropogenic factors that have driven them, the authors combined data from 13 years of in-water visual surveys of turtle abundance near 53 islands, atolls, and reefs throughout the U.S. Pacific. During a survey, a slow-moving boat tows a pair of divers at about 15 meters below the surface, where they record details of habitat and sea life as it comes into view. In all, the surveys covered more than 7,300 linear kilometers and observed more than 3,400 turtles of the two species.

Survey data showed that American Samoa had the highest density of hawksbills, while the Pacific Remote Islands Area, a mostly uninhabited region about a thousand miles southwest of Hawaii, had the most green turtles. Hawksbill numbers were far lower (< 10%) than green turtle counts, indicating that many conservation threats still exist for this species. Density of green turtles were driven primarily by ocean temperatures and productivity, but suggested effects from historical and present-day human impacts. Over the survey period, green turtle populations were either stable or increased. The lowest density but the highest annual population growth was found in the Hawaiian Islands, suggesting that protective regulations may be paying off in allowing green turtle populations to rebound.

Becker adds: “This study represents one of the largest sea turtle population surveys ever conducted, filling critical gaps on in-water abundance and drivers of population density. Across the tropical Pacific several locations held impressive densities of sea turtles, and in all regions densities were driven by bottom-up forces like ocean temperatures and productivity and top-down forces such as human impacts.”

Advertisements

Rare Cambodian turtle freed into the wild


This 24 April 2019 video says about itself:

Rare Giant Soft-Shell Turtle Released Into the Wild | Nat Geo Wild

A Cambodian community is attempting to save this endangered species, which can grow to the size of a small sofa.

Galapogos giant tortoises and climate change


This 23 March 2019 video says about itself:

Tracking Giant Galapagos Tortoises | BBC Earth

From the Ecological Society of America:

Giant tortoises migrate unpredictably in the face of climate change

Unlike many migratory species, Galapagos giant tortoises do not use current environmental conditions to time their seasonal migration

April 18, 2019

Summary: Researchers use GPS to track the timing and patterns of giant tortoise migration over multiple years. The tortoises often take the same migration routes over many years in order to find optimal food quality and temperatures. The timing of this migration is essential for keeping their energy levels high, and climate change could disrupt a tortoise’s ability to migrate at the right time.

Galapagos giant tortoises, sometimes called Gardeners of the Galapagos, are creatures of habit. In the cool dry season, the highlands of the volcano slopes are engulfed in cloud which allows the vegetation to grow despite the lack of rain. On the lower slopes, however, there is no thick fog layer, and vegetation is not available year round. Adult tortoises thus spend the dry season in the higher regions, and trek back to the lower, relatively warmer zones where there is abundant, nutritious vegetation when the rainy season begins.

The tortoises often take the same migration routes over many years in order to find optimal food quality and temperatures. The timing of this migration is essential for keeping their energy levels high, and climate change could disrupt a tortoise’s ability to migrate at the right time.

In the Ecological Society of America’s journal Ecology, researchers use GPS to track the timing and patterns of tortoise migration over multiple years.

“We had three main goals in the study,” says Guillaume Bastille-Rousseau, lead author of the paper. “One was determining if tortoises adjust their timing of migration to current environmental conditions. Two, if so, what clues do they use to adjust the timing, and, three, what are the energetic consequences of migration mis-timing for tortoises?”

The researchers expected the migrations to be timed with current food and temperature conditions because many other migratory species operate that way. Bastille-Rousseau says “many animals, such as ungulates, can track current environmental conditions and migrate accordingly — what researchers sometime refer to as surfing the green-wave.”

Contrary to the researchers’ expectations, however, migration is weakly associated with current conditions such as fog, rain, and temperature. For instance, if it is unseasonably arid, it appears the tortoises do not take that variation into account when deciding it is time to migrate. It is unclear at this point whether they are basing their migration decisions on memories of past conditions or if they are simply incorrectly assessing current local conditions.

Bastille-Rousseau says the team is surprised by the mismatch, stating “tortoise timing of migration fluctuated a lot among years, often by over two months. This indicates that migration for tortoises may not just be about foraging opportunities. For example, female tortoises have to make decisions related to nesting, and we still have a lot to learn about migration in giant tortoises.”

Fortunately, this sub-optimal timing may not yet have critical impact on tortoise health. Potentially due to their long lives of up to 100 years and large body size, bad timing of migration has smaller consequences for giant tortoises compared to small, short lived animals. Giant tortoises can go up to a year without eating and survive, while other migrating species must eat more regularly to sustain their energy levels.

Giant tortoises are important ecosystem engineers in the Galapagos, responsible for long-distance seed dispersal, and their migration is key for many tree and plant species’ survival. How the tortoises’ variation in migration timing will affect the rest of the ecosystem is still unclear. Because tortoises do not seem to be tracking annual variation in environmental conditions, it is quite possible that the mistiming of migration will keep increasing in the future.

“One concern is that at some point in the future,” Bastille-Rousseau adds, “migration may not be an optimal strategy for tortoises. There may be a reduction in the number of individuals doing these long-distance movements. This would likely have cascading consequences for the whole ecosystem.”

THE CLIMATE KIDS ARE ALL RIGHT The last five years were the five hottest on record. The amount of carbon dioxide in the atmosphere has soared past 410 parts per million. As many as 150 species die off each day. As the call for action grows louder, the youth climate movement ― which scientists say has moved the needle on action to address the climate emergency ― is taking center stage. [HuffPost]

HAWAII BEACHES MAY SOON BE UNDERWATER Hawaii’s iconic Waikiki Beach could soon be underwater as rising sea levels caused by climate change overtake its white sand beaches and bustling city streets. State lawmakers are trying to pass legislation that would spend millions for a coastline protection program. [AP]

A new Stanford University study shows global warming has increased economic inequality since the 1960s. Temperature changes caused by growing concentrations of greenhouse gases in Earth’s atmosphere have enriched cool countries like Norway and Sweden, while dragging down economic growth in warm countries such as India and Nigeria: here.

Sea turtles video


This 15 February 2019 video says about itself:

Sea Turtles 101 | National Geographic

Sea turtles have existed since the time of the dinosaurs. Find out about the ancient mariners’ oldest known ancestor, how certain adaptations may have helped the reptiles survive, and the conservation efforts being made to save these creatures.

Leatherback turtles, research and conservation


This video is called National Geographic Animals 2017 | Giant Leatherback Sea Turtle! | Wildlife Documentary.

From the University of Maryland Center for Environmental Science in the USA:

Tracking turtles with telemetry

New model predicts where Eastern Pacific leatherback turtles travel to help protect endangered species

March 14, 2019

A new model has been created that can forecast the location of Eastern Pacific leatherback turtles along the coast of Central and South America in an effort to decrease bycatch mortality of this critically endangered and ecologically important species.

Scientists from University of Maryland Center for Environmental Science have developed a unique model in collaboration with Dr. George Shillinger at the nonprofit Upwell Turtles that can predict on a monthly basis where Eastern Pacific leatherbacks are most likely to be residing.

“Upwell was created to address an unmet need in sea turtle conservation: protecting turtles in the ocean, where they spend most of their lives. By engaging new consistencies and improving access to predictive tools, like the South Pacific Turtle Watch, we can reduce the threats turtles face at sea from fisheries interactions,” said Upwell Executive Director Dr. George Shillinger.

A website called South Pacific Turtle Watch will be launched in coordination with this study as an online resource to educate the public on the importance of protecting leatherback turtles and to allow public access to the models predicting Eastern Pacific leatherbacks’ location.

By providing countries connected to this species with this information, scientists hope for a decrease in the accidental capture of Eastern Pacific leatherback turtles by fisheries, a threat that is partially responsible for the species’ 98 percent decline since the 1980s.

“A lot of managers and government agencies in Central and South America have been asking for something. They know leatherback populations are declining, they know fisheries have a role in it, so they have been thirsty for some information about what they can do so leatherbacks don’t disappear,” said study author Aimee Hoover of the University of Maryland Center for Environmental Science.

The decline in this leatherback turtle population is not all to blame on fisheries, but the purpose of this study was to produce data to inform potential management strategies to help both turtles and fishermen.

“Fishers aren’t targeting leatherbacks and other marine turtle species,” said Shillinger. “Incidental capture of turtles consumes time, damages equipment, and attracts unwanted negative attention. The South Pacific Turtle Watch tool will enable fishers to take proactive measures to reduce their bycatch, potentially reducing the risk of fisheries-turtle interactions within high-use turtle habitats.”

Leatherback turtles, which can live over 45 years, grow up to 2000 pounds, and reach lengths over 9 feet, prey exclusively upon gelatinous zooplankton. As such, leatherbacks play an important role as a keystone species in controlling jellyfish populations, which may be increasing as a result of changing climatic conditions and food web alterations from fisheries pressures. Jellyfish are not only important for the diet of these turtles but can damage fishermen’s nets and boats if they are caught in high numbers. It is estimated that less than 1,000 adult females of the species remain.

This study is the first segment of a two-part project hoping to improve leatherback turtle management strategies. This portion focused on modeling turtle residence time — how long the individual stays in one location — through satellite telemetry. Researchers are currently working on a complementary paper that will predict leatherbacks’ location through observer data collected from trained observers and volunteers on fishing vessels that encounter this critically endangered species.

Satellite telemetry technology allows for measurements and data to be collected remotely, which allows these free-moving creatures to be tracked from a distance for years once they are tagged with satellite transmitters. Turtles tagged in Costa Rica, Mexico and Peru were tracked for up to two years during a period spanning over two decades. In total, tracks from 45 different leatherbacks were used in the final analyses of this study.

The model predicts the seasonal route of leatherbacks, who migrate south from their nesting beaches into the South Pacific Gyre and then travel north to warmer temperatures near the equator during the winter, forming a circular pattern. Leatherback turtles are predicted to either travel down along the coast of Central America or travel out to the Pacific Ocean and south.

This statistically advanced model confirms previous tracks that have been developed and allows monthly models to be predicted based on current environmental conditions of leatherbacks’ habitat, such as temperature, upwelling and sea surface height. Upwelling is of particular interest to turtles as it refers to the process of nutrient rich waters being brought to the surface that leads to increased abundance of prey, like gelatinous zooplankton.

“To our knowledge we’re paving the way by incorporating dynamic environmental variables,” commented Hoover. “Every month we’re looking at a different temperature and environment over time to help model our predictions based on the changing environment this animal is experiencing.”

‘Extinct’ Galapagos tortoise rediscovered


This 20 February 2019 video in French is about the rediscovery of the Chelonoidis phantastica giant tortoise on the Galapagos islands.

Translated from Dutch NOS TV, 20 December 2019:

Giant tortoise species seen again for the first time since 1906

An extinct giant tortoise has been found in the Galapagos Islands. This species had not been seen since 1906. That is why scientists assumed that a volcanic eruption had eradicated the turtle species.

It is a female Chelonoidis phantastica, a subspecies of the Galapagos giant tortoise. It only lives on the island of Fernandina. The female was discovered by local conservationists.

The proud Minister of the Environment of Ecuador announced the find on Twitter. The archipelago is part of this South American country.

Lots of striking species of lizards, iguanas and giant turtles live on the Galapagos Islands. The flora and fauna on the islands were an important source of inspiration for Charles Darwin‘s book The Origin of Species, in which he explained his theory of evolution.