Climate Change, Conservation, Nature, Science

Great Barrier Reef May Be More Resilient Than Once Thought

New research indicates that the Great Barrier Reef may be more resilient than once thought--but that doesn't mean there's no reason for concern.
A sea turtle swims above the Great Barrier Reef. Photo: Shutterstock

New research gives us reason for hope that the Great Barrier Reef is not set up for doom, despite the extensive damage and bleaching of the reef itself.

Scientists at the University of Queensland, the Australian Institute of Marine Science, CSIRO, and the University of Sheffield have recently published a paper with the results of an extensive study in which they found that there are still 100 reefs on the Great Barrier Reef that could help to promote the regional recovery of its ecosystem.

The Great Barrier Reef consists of more than 3,800 individual reefs. These reefs have suffered unprecedented coral bleaching events over the past couple of years. Additionally, the coral-eating crown-of-thorns starfish has also been plaguing the reef system.

The new study shows that there are 100 reefs that fulfill three criteria to promote coral recovery. First, they should lie in cool areas and rarely experience damage from bleaching, thus being able to supply larvae to as many reefs as possible. In addition, reefs should be located in areas of current that can supply coral larvae to as many reefs as possible; and they should not spread the larvae of the crown-of-thorns starfish.

“Finding these 100 reefs is a little like revealing the cardiovascular system of the Great Barrier Reef,” said study author Professor Peter Mumby. “Although the 100 reefs only make up 3 percent of the entire GBR, they have the potential to supply larvae to almost half of the entire ecosystem in a single year.”

“The presence of these well-connected reefs on the Great Barrier Reef means that the whole system of coral reefs possesses a level of resilience that may help it bounce back from disturbances, as the recovery of the damaged locations is supported by the influx of coral larvae from the non-exposed reefs,” said study lead author Dr. Karlo Hock.

Dr. Hock added that this does not mean the Great Barrier Reef corals are safe or in great condition. There is still plenty of reason for concern when it comes to the health of the GBR. “The fact that the study only identified around 100 of these reefs across the entire 2,300-km length of the massive Great Barrier Reef emphasizes the need for both effective local protection of critical locations and reduction of carbon emissions in order to support this majestic ecosystem.”

However, the research also indicates that focusing efforts on these healthy and well-connected reefs, and continual monitoring of those reefs’ health, may be a step toward restoration of the reef. The ecosystem is still vulnerable to the effects of climate change and predation. So, there’s reason for hope, but that optimism must remain guarded until the forces that caused the death of vast swathes of the reef system can be controlled.

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Nature, oceans

New Study Says Sea Animals Eat Plastic Because of Its Taste

A new study says that sea animals may like plastic because it tastes good.
These coral polyps are feeding–and most likely ingesting lots of microplastics in the process. Photo: Shutterstock

Scientists have long known that plastic in the oceans can mimic prey, causing huge problems for sea life. But what they didn’t know is that even corals eat plastic.

Corals don’t have eyes, and they don’t move from their location, so why would they eat plastic? Apparently because it tastes good, according to a recent study from Duke University.

This taste factor may also be true for other sea life. After all, anecdotal evidence suggests that our cats and dogs eat plastic because they like the taste and/or the texture, so why wouldn’t sea life have the same reaction?

Microplastics, tiny pieces of weathered plastic less than 5 millimeters in diameter, have been accumulating in the world’s oceans for 40 years or more, and now they’re ubiquitous in the marine environment. They don’t just pose threats to corals, they also pose a threat to foraging sea animals including birds, turtles, mammals, and invertebrates.

Because plastic is largely indigestible, it can lead to intestinal blockages, create a false sense of fullness, or reduce energy reserves in animals that eat it.

“About eight percent of the plastic that coral polyps in our study ingested was still stuck in their guts after 24 hours,” said study co-lead author Austin S. Allen, a Ph.D. student at Duke.

Plastics can also leach hundreds of chemical compounds into the bodies of the creatures that eat it and into the environment as well. The biological effects of most plastic compounds are unknown, but we do know that some have already been shown to cause harm. For example, phthalates are confirmed environmental estrogens and androgens—that is, hormones that affect sex determination.

“Corals in our experiments ate all types of plastics, but preferred unfouled microplastics by a threefold difference over microplastics covered in bacteria,” Allen said.

“When plastic comes from the factory, it has hundreds of chemical additives on it. Any one of these chemicals or a combination of them could be acting as a stimulant that makes plastic appealing to corals,” said Alexander C. Seymour, a GIS analyst at Duke, who co-led the study with Allen.

The researchers hope their findings will encourage more scientists to study the role taste plays in determining why marine animals ingest microplastics.

“Ultimately, the hope is that if we can manufacture plastic so it unintentionally tastes good to these animals, we might also be able to manufacture it so it intentionally tastes bad,” Seymour said. “That could significantly help reduce the threat these microplastics pose.”

Nature, Science

The World’s Oceans Now Have A Health Record

The oceans now have a health record, thanks to a team of scientists at UC Santa Barbara

Thanks to a team of researchers at UC Santa Barbara, the world’s oceans now have a health record.

And that health record is revealing clues about what might be behind ocean improvements or declines.

Analyzing data from 220 countries, the team gathered five years’ worth of ocean “vital signs” in a variety of areas ranging from water quality to food provision to tourism potential in order to create an Ocean Health Index. Their conclusion: While ocean health appears to be stable, the oceans around many of the countries analyzed are changing for the worse.

“With five years of assessments about where oceans are healthy and not as healthy, we finally have enough information to get a clear signal of what might be causing changes,” said study lead author Ben Halpern, executive director of the National Center for Ecological Analysis and Synthesis at UC Santa Barbara.

Countries like Indonesia, Mexico, and Samoa, that are seeing improvements in their oceans are taking action to make things better, including improving management of wild-caught fisheries and creating marine protected areas.

On the other hand, the countries that saw a decline in ocean health where in consistent political turmoil. Many Arctic and sub-Arctic countries are seeing declines as well, due to the fact that coastlines are losing sea ice, which is a natural protection from storm damage and erosion.

“The Ocean Health Index created the first opportunity any of us has had to measure the health of our oceans in a comprehensive way and track changes with a single measure,” Halpern said.

According to the researchers, the index has scored the oceans’ overall health staying steady at a 71 out of 100. This shows that while the oceans aren’t dying, they aren’t thriving, either. The team will continue to collect data on ocean health every year.

“We believe the Ocean Health Index gives reason for hope by providing a detailed diagnosis of the state of ocean health and a framework that allows countries to identify and prioritize the most necessary resilience actions to improve ocean health,” said study co-author Johanna Polsenberg, senior director of governance and policy for Conservation International’s Center for Oceans. “This is where our work is most valuable. It helps to identify and highlight the necessary steps to ensure a healthy ocean into the future.”

I don’t know about you, but after seeing all the news about dying reefs, pollution, and overfishing, I’m surprised the oceans are as healthy as they are. Hopefully this new information will help governments and scientists to improve their health.

Nature, Science

DNA Evidence Helps Discover New Whale Species

A new beaked whale species has been discovered in the North Pacific.
Photo: Shutterstock

Beaked whales, which have pointed noses like their dolphin cousins, are not very well understood compared to other types of whales. They aren’t seen as often or studied as much, and scientists have discovered several species just in the past few decades. Now we’re about to add another to that list thanks to some recent discoveries using genetic research.

The Baird’s beaked whale has been known for a while, and is among the species caught by Japanese whaling crews. Every once in a while, though, they find smaller, black specimens, which until recently were just assumed to be Baird’s beaked whales. But their size, up to about 25 feet, and their distinct coloration led some scientists to posit that they might be a different species.

A recent study of genetic information from 178 whales once classified as Baird’s beaked whales, or as an unknown potential species, found that eight of those samples are in fact from a newly discovered species.

Though very similar to the Baird’s, this new species is actually more closely related to another species, the Arnoux’s beaked whale from the Southern Hemisphere. The new species also has a smaller range, from northern Japan to the Aleutian Islands in Alaska, though we don’t know much more about them yet.

“The implication of a new species of beaked whale is that we need to reconsider management of both species to be sure they are sufficiently protected, considering how rare the new one appears to be,” said Erich Hoyt, a research fellow with Whale and Dolphin Conservation in the United Kingdom, and co-director of the Russian Cetacean Habitat Project.

Beaked whales dive deep to feed on bottom fish, squid, and other creatures that live thousands of feet below sea level. We can make some basic arguments about the whales based on what we know, do far, but with so few samples it’s hard to know much more.

While finding a new species of whale is very exciting, it highlights just how little we actually know about the ocean and its inhabitants. Hopefully further study can tell us more about this new species, which still has to be officially recognized and named.

Climate Change, Nature, ocean

Cephalopod Populations Grow in Warming Oceans and Threaten Ecological Balance

Giant Australian Cuttlefish are one of the cephalopod species experiencing population growth due to an increase in ocean temperatures caused by global warming.
Giant Australian Cuttlefish are one of the cephalopod species experiencing population growth due to an increase in ocean temperatures caused by global warming. Photo: Eureka Alert | Scott Portelli, Wildlife Photographer.

By now, we’re all used to reading stories about how global climate change is harming life on Earth. This increase in temperature is a big problem for the world’s oceans.

Rising water temperatures are displacing species and leading to coral bleaching. It’s not all bad news. There are some creatures who are benefiting from climate change.

Cephalopods, which include octopi, squid, and cuttlefish, have been on the rise over the last sixty years. Although nobody is sure why this is happening, between 1953 and 2013, the population of 35 different species has been increasing.

Cephalopods grow quickly, they don’t live very long, and they are very sensitive to environmental change, making them quite adaptable. This explains their rapid expansion in numbers.

Whether warming oceans are entirely responsible is unknown, but it’s not likely to be that simple. Ecology is complex, and there are probably a number of factors at work in this population growth.

Another question is how this rise in population will impact other creatures that share ecosystems with these cephalopods. Cephalopods are voracious predators. Larger populations of them could devastate their prey species and related species before the new population reaches an ecological balance.

Cephalopods aren’t apex predators there are other creatures who prey on them. Their larger numbers might provide a surplus of prey for sharks and other creatures. Humans could be encouraged to harvest more of them without damaging their populations. Though making business decisions on something that might be a quirk can be risky.

More research needs to be done to understand this population shift. How strongly are these population growths tied to global temperature and human activity?

Will they continue to change in proportion to the global temperature, and how will efforts to reduce climate change impact them? Luckily scientists all over the world are investigating these issues.

Environmental Hazards, Nature, Science

Over Half of Sea Turtles Have Eaten Plastic

Sea turtles are threatened when they ingest plastic trash found in the ocean. This decaying plastic bag looks like a jellyfish and a seat turtle would consider it food.
Sea turtles are threatened when they ingest plastic trash found in the ocean. This decaying plastic bag looks like a jellyfish and a sea turtle would consider it food. Photo: seegraswiese | WikimediaCC.

According to a recent study, roughly 52% of turtles worldwide have ingested some human rubbish, generally plastic. This revelation comes quickly after a study that found 60% of seabird had also ingested plastic in some form or another.

When turtles eat garbage, it has the potential to get lodged in their gut, where it can cause physical harm, take up space within their digestive tract, or even release toxic chemicals into their tissues. The rubbish comes from the roughly 12 million tonnes of plastic that finds its way into the ocean annual.

That’s a lot of plastic and, unfortunately, a lot of it can be mistaken for food by unaware turtles. In the case of olive ridley turtles, this can be especially dangerous as these turtles have a wide distribution, and tend to feed in the open ocean where debris accumulates. They often eat jellyfish and other floating creatures and could easily mistake bits of trash for their regular prey.

The waste problem is especially severe in Australia and North America, both of which host a wide variety of sea turtles, and have large urban populations, the kind which tends to produce trash that ends up in the ocean. As such, people living on these continents have to find ways to reduce the amount of waste that makes it into the sea, beyond what efforts are already being made.

As with seabirds, the number of turtles that have ingested plastic or another type of trash is expected to continue rising as long as pollution levels stay as they are. Reduced trash means fewer animals will be in harm’s way. But researchers were sure to warn that if turtles and birds were ingesting plastic with this kind of frequency, other animals surely are as well. Although studies haven’t been performed on fish or aquatic mammals, it’s only a matter of time until we start finding plastic in their digestive tracts too.

Climate Change, Nature

Saharan Dust is Part of the Global Climate and Ecosystem

The desert wind called Calima carries sand from the Sahara Desert across the ocean and into the atmosphere, as seen here on the Canary Islands.
The desert wind called Calima carries sand from the Sahara Desert across the ocean and into the atmosphere, as seen here on the Canary Islands. Photo: Frerk Meyer | FlickrCC.

The Sahara Desert generates more dust than any other desert in the world, and that dust impacts the globe in a number of ways. A lot of it ends up in the ocean, where it introduces nutrients that otherwise might not get there, and some of those same nutrients end up falling over land as well. The dust also blocks or reflects sunlight, which can impact the formation of clouds and hurricanes.

By exploring data collected over the last century, scientists have been able to track what kinds of impact the dust has had in the past. They found that events like El Niño, the North Atlantic Oscillation, rainfall in the Sahel region of Africa, the Sahara Low Heat, and even the Intertropical Convergence Zone, can all impact how much dust is generated, where it moves, and how quickly.

The strength of a Saharan wind called the Harmattan, which blows across the massifs of North Africa, is particularly important to the process. The various other processes and events work to change the intensity of the Harmattan, which in turn determines how the dust works out each year.

Using the data they had, the researchers figured out what was happening as far back as 1850, and then they looked to the future to try and predict how things will work out over the rest of the century. What they found is that there will be a decrease in dust generation, although they aren’t entirely sure yet what that means for the rest of the world.

On the one hand, it could have some unseen benefit for humans, but that might come at the cost of reduced nutrients in soil and ocean. Maybe more of the dust will stay in Africa and help enrich arable lands there.

It could also result in a general warming of the tropical North Atlantic, which might be more suitable for hurricanes and could have a very different impact.