Climate change is affecting sea turtles in an unusual way: sex. The sex of hatchlings, that is.
According to a study by Florida State University, rising global temperatures are causing a gender imbalance. Scientists researched Brazilian loggerhead turtles and found that the warmer temperatures cause higher incubating temperatures, which leads to more female hatchlings.
Optimal hatching temperatures are between 75.2 to 93.2 degrees Fahrenheit, but temperatures below 85.1 degrees results in more male turtles and temperatures above yield more females.
Assistant Professor of Oceanography at Florida State University Mariana Fuentes said:
“We’re concerned we’re going to have a feminization of marine turtles. This study came from the need to understand the current sex ratio being produced at loggerhead nesting grounds to establish baseline parameters as climate change progresses and to identify beaches that produce a higher proportion of males.”
Researchers believe projected increases in temperature will cause gender imbalance in marine turtle populations to worsen. Fuente and her team will move forward trying to identify the best practices to protect the turtles. They will coordinate with government officials and conservationists in Brazil to create conservation plans, working to make sure this imbalance does not negatively impact the species.
What is one of the baleen whale’s favorite food? Krill. But as carbon dioxide levels rise, it creates a big problem for these tiny crustaceans.
Studies at the Australian Antarctic Division agency found that krill eggs do not hatch when exposed to higher CO2 levels. In fact, Antarctic Division biologist So Kawaguchi believes there will be a 20-70% decline in Antarctic krill populations by the year 2100 and a complete extinction by 2300. Dr. Kawaguchi says:
“Higher levels of carbon dioxide in the water mean greater levels of ocean acidification. This interrupts the physiology of krill. It stops the eggs hatching, or the larvae developing.”
Although krill are tiny creatures, they are one of the most abundant species on earth and have a massive role in the marine ecosystem. They sit at the bottom of the ocean food chain and serve as sustenance for (or sustenance for the prey of) several animals such as fish, squid, sea birds, seals and whales. If krill die off – or populations diminish significantly – it will have a serious, negative impact on baleen whales and much of the ocean’s ecosystem.
It’s not too late, however, as Kawaguchi suggests a moratorium on fishing in the region until the agency can dive deeper into the effects ocean acidification has on krill.
Over 9,000 feet below the surface, off the coast of Puerto Rico, scientists saw some creatures for the first time ever. In April 2015, a team of scientists embarked on a National Oceanic and Atmospheric Administration (NOAA) expedition that captured incredible images of these deep-sea creatures. The ship, called the Okeanos Explorer, journeyed into largely uncharted ecosystems, including the seafloor, and investigated what lives in these unknown and little-known areas.
Polar bears are spending more time on land than ever before. To be exact, bears around the Chuchki Sea are spending a month longer on land during the summer, according to a new study.
Research wildlife biologist with the Alaska Science Center of the U.S. Geological Survey and lead author Karyn Rode says:
“They are spending approximately 30 more days on land, which is pretty substantial in the summer. Where they come on land during the summer is changing because of the ice conditions…They’re either sitting, laying or standing. They aren’t moving around very much to forage,” she said. “When we look at this activity sensor, it’s incredibly low.”
The researchers analyzed data from radio collars on 103 female polar bears between 1986-1996 and compared them to data from 47 bears in 2008-2013. They found that bears now spend a month longer on land, that almost twice as many bears spend their summers on land and that more than 90% of time on land is spent resting.
So far, this has not affected the bears’ nutrition, but there is debate about whether polar bears can sustain themselves on a land-based diet. As the summer sea ice continues to melt, polar bears will likely spend more and more time onshore and, unfortunately, recent studies show that polar bears’ cannot sustain themselves during long periods of famine. In addition, more time onshore will increase the chance of conflict with humans.
“The results of our study are consistent with studies in other regions where polar bears have experienced substantial sea ice loss. As sea ice loss occurs, polar bears increasingly use land habitats where they have minimal to no access to their marine mammal prey and are increasingly likely to interact with humans.”
Nearly half of all life under the sea has disappeared in the past 50 years.
A new study by the World Wildlife Fund and researchers at the Zoological Society of London found that global populations of marine species have declined by 49% since 1970 due to pollution, habitat loss, overfishing and climate change.
Researchers were able to approximate this drastic decline using data that was collected from 2,337 individual sources, including population estimates from scientific studies and databases.
The study also found that some fish species people rely on for food – like tuna, bonito and mackerel – has declined by as much as 74%. Shark finning and industrial fishing have wiped out shark and ray populations to the point where one in four species are now threatened by extinction. And the number of sea cucumbers, a luxury food in Asia, have dropped by 98% in the Galápagos and by 94% in the Egyptian Red Sea.
Furthermore, industrial pollution and plastic contamination have destroyed marine habitats and caused the death of endangered sea turtles and other wildlife. Fossil fuels that accelerate the acidifcation of the oceans has led to the degradation of coral reefs, which support 25% of marine species on top of 400 million people. The world’s coral reefs will disappear if ocean temperatures continue rising at the current rate.
The report’s findings include a lot of bad news, but there is a silver lining. The world’s leaders and nations can use this information to turn things around by halting illegal fishing, cutting greenhouse gas emissions and protecting critical marine habitats like the remaining coral reefs. Director general of WWF International Marco Lambertini said in a statement:
“The ocean is a renewable resource that can provide for all future generations if the pressures are dealt with effectively. If we live within sustainable limits, the ocean will contribute to food security, livelihoods, economies and our natural systems.”
The BP oil spill in the Gulf of Mexico is still having devastating effects, even six years later.
A new study found that dolphins in the Gulf aren’t able to have as many babies because of the 2010 BP oil spill, also known as the Deepwater Horizon oil spill. The study also found that this impact could last for generations.
Researchers examined bottlenose dolphins in a previously contaminated area and found that only 20% of them produced viable calves. These dolphins were from Louisiana’s Barataria Bay, while other dolphins from Florida’s Sarasota Bay were found to have a pregnancy success rate of 83%, according to another study.
Furthermore, the Barataria Bay dolphins experienced lower longevity, with a survival rate of just 87% versus 96% in a similar bottlenose population. Other dolphin populations in the Gulf are suffering similarly, including those in the Mississippi Sound.
Executive director of the National Marine Mammal Foundation and the study’s co-author Cynthia Smith told TakePart:
“We are very concerned about the high rate of reproductive failures among Barataria Bay dolphins, as recovery of the population depends on successful reproduction. Barataria Bay dolphins were more likely to be underweight, have moderate-severe lung disease, and have an impaired stress response. Any one of these conditions could put a pregnancy at risk, as well as make it difficult to care for a newborn.”
The BP oil spill was the worst marine oil spill in U.S. history with around 4.9 million barrels of oil spilling into the Gulf. Dolphins and other marine creatures were exposed to oil by ingestion, absorption through the skin and inhalation.
In February, a government-funded study showed that since 2010, 1,305 dolphins were discovered stranded on Gulf shores and 94% of them were found dead – this represents the longest marine mammal Gulf die-off ever.
“Whether the observed reproductive failures are directly related to oil exposure or indirectly related to the oil through a cascade of other health impacts to the adult females, cannot currently be determined. However, given the documented poor health of Barataria Bay dolphins…it is unsurprising to find impacts on reproduction as well.”
If history is any indication of what’s to come, the long-term effects of the BP spill could be disastrous. We could see drastic declines in the populations of dolphins – and other species too – without recovery for decades.