Marine Life & Conservation
App Set To Match The Oceans’ Plankton
A study is calling on the world’s sailors to help map the oceans’ phytoplankton, microscopic plants that form the bedrock of marine food chains.
Researchers have developed an app for people to submit readings from Secchi disks – a method used since 1865.
The team hopes the data will help them understand what is happening beneath the waves.
They have been “astonished” by the response so far but are hoping for more readings from the southern hemisphere.
“The reason the project came about was because, in 2010, some Canadian scientists wrote a paper that suggested that the phytoplankton in the world’s oceans had declined by 40% since the 1950s,” explained project leader Richard Kirby, a research fellow at Plymouth University’s Marine Institute.
“If true, this is a dramatic decline. As phytoplankton starts the food chain, they dictate the productivity at every level above,” he observed.
“Ultimately, phytoplankton determines the amount of fish in the sea and the number of polar bears on the ice.”
Marine biologists have been using the Secchi disk method to measure the abundance of phytoplankton for 150 years.
The white disk measures 30cm (1ft) in diameter and is lowered into the water on the end of a tape measure. When it is no longer visible from the surface, the reading – known as the Secchi depth – is recorded.
“It is a very robust method and not prone to error and it is a good measure of phytoplankton abundance,” said Dr Kirby.
“Away from estuaries and more than a kilometre from the coast, the main influence on water clarity is phytoplankton.”
He explained how he had the idea of setting up a citizen science project: “It occurred to me sat at my desk that while there are a lot of scientists, there are not that many that are marine scientists, and fewer still that go to sea.
“And the ones that do go to sea do not go out very far. If they do go out far, they rarely go back to the same place.
“I thought that there are an awful lot of sailors out there; day sailors, cruising sailors. Many of these sailors will sail the same waters and take the same route time and time again.”
Dr Kirby, and colleagues Drs Nicholas Outram and Nigel Barlow from the University’s School of Computing and Mathematics, developed the Secchi Disk App that would store a reading while at sea before uploading it to a database once the smartphone was back within range of a mobile phone network.
“We can now collect Secchi depth measurements from all over the world’s oceans and add that to the data from the 1860s to make a continuous – with a slight dip – record to see what is happening to the phytoplankton in the oceans,” he said.
The database, managed by Dr Sam Lavender, is accessible, free-of-charge, from the project’s website.
The reason for collecting measurements via the Secchi method, Dr Kirby explained, was because the Canadian team’s findings proved to be quite controversial among scientists.
“Some said that they did not see any similar decline, while others said they saw an increase rather than a decline,” he said.
The study was criticised because it combined Secchi disk measurements with data gathered using modern technology that became available to scientists in the late 20th Century.
Despite the criticism, the authors have defended their findings, saying the dramatic decline was a result of sea surface temperature.
“They said that the warming had increased stratification so fewer nutrients were reaching the oceans’ surface, and so there was less phytoplankton growth,” Dr Kirby said.
He added that in the waters around UK shores, observations showed that phytoplankton were appearing at different times of the year.
He said that changes in the seas’ seasons had potential consequences for life beneath the waves.
“This is changing the coupling in the marine ecosystem. Evolutionarily, everything is synchronised – just as it is on land.
“When the timings start altering, even by just a fraction, then things no longer work through the food chain.”
To help raise awareness of the vital role phytoplankton plays in marine and terrestrial food chains, Dr Kirby has written and produced a short film called Ocean Drifters, which has been sent to every secondary school in England.
Narrated by Sir David Attenborough, the film also explains how plankton is responsible for the familiar smell of “sea air”, and how the tiny organisms are involved in the formation of clouds.
Source: www.bbc.co.uk/news
Photo: Richard Kirby
Blogs
Evolution of Manatees in Florida
Op-ed by Beth Brady, PhD, Senior Science and Conservation Associate, Save the Manatee® Club
Recent news articles and broadcasts have claimed that manatees are not native to Florida or only arrived on Florida’s west coast in the 1950s. These claims, based on limited anthropological records, point to where manatees were historically exploited by humans and assume that a lack of evidence means manatees were absent from certain areas. However, absence of evidence is not evidence of absence—it’s like looking for stars in the daytime; just because you can’t see them doesn’t mean they’re not there. Moreover, genetic and fossil evidence indicate manatees have been present in Florida for the last 12,000 years.
The Florida Fish and Wildlife Conservation Commission (FWC), which manages Florida manatee populations, has created a manatee timeline highlighting key dates and notable information about manatee presence in Florida (https://myfwc.com/education/wildlife/manatee/timeline/). Historical records suggest that manatees have been observed in Florida as far back as the 1500s, with some details presented by the Florida Fish and Wildlife timeline aligning with evidence presented in the publication.
Manatee species, such as the African manatee and the Antillean manatee, continue to be poached by humans (Marsh et al., 2022). As a result, these species are difficult to observe in the wild and may adapt by foraging at night to avoid human encounters (Rycyk et al., 2021). This behavior could help explain why historical Florida manatee populations that were hunted by humans are absent from middens and rarely mentioned in historical accounts.
Further, the publication only briefly touches on the paleontological record and genetic evidence, which indicate that manatees have existed in Florida for a much longer period. Fossil and genetic evidence reveal a rich history of manatees in Florida. Manatees belong to the order Sirenia, which includes the Amazonian, African, and West Indian manatee species. While Sirenian fossils have been found globally, only Florida and the Caribbean contain specimens from every epoch over the past 50 million years (Reep and Bonde, 2006). The modern manatee, as we know it, emerged in the Caribbean about 2 million years ago (Domning, 1982).
The evolution of manatees during the Pleistocene epoch provides valuable insights into how environmental changes shaped their distribution and genetic diversity. During the Pleistocene epoch (2.59 million to 11,700 years ago), there were roughly 20 cycles of long glacial periods (40,000–100,000 years) followed by shorter interglacial periods lasting around 20,000 years. At the start of these warmer periods, Caribbean manatees migrated northward with the warming waters (Reep and Bonde, 2006). Water currents and thermal barriers isolated these manatees from populations in Mexico and the Caribbean, leading to genetic divergence. Fossil evidence indicates that Trichechus manatus bakerorum lived in Florida and North Carolina about 125,000 years ago but did not survive the last glacial period, which began 100,000 to 85,000 years ago (Domning, 2005). This subspecies was eventually replaced by modern Florida manatees.
This evolutionary theory is further supported by genetic evidence. Research indicates that Florida manatees trace their evolutionary origins to Caribbean ancestors that migrated northward over the past 12,000 years (Garcia-Rodriguez et al., 1998). A 2012 study by Tucker et al. reinforces this theory, showing higher genetic diversity in manatees on Florida’s west coast compared to those on the east. Over time, core populations migrated northward, with some groups moving south and east along the Florida coastline before heading north along the Atlantic. This migration pattern left the west coast population with greater genetic diversity, while the east coast population retained only a smaller subset. These findings suggest that the founding population of Florida manatees—arriving approximately 12,000 years ago—originated along Florida’s southwestern coast, which became the center of the state’s manatee population (Reep and Bonde, 2006). The process of vicariance further supports this hypothesis; as geographic and ecological barriers emerged, they likely isolated the Florida manatee populations from their Caribbean ancestors. This isolation likely limited migration back and forth between regions, fostering the establishment of local populations in southwestern Florida.
Manatees are not only a cherished symbol of Florida’s natural heritage but also a species with deep evolutionary and historical ties to the region. In sum, despite recent claims questioning their nativity, extensive fossil and genetic evidence confirms that manatees have been present in Florida’s waters for thousands of years, with ancestors dating back over 12,000 years. We agree with the authors of the published article that protecting these iconic creatures and their habitats is essential to preserving Florida’s unique ecological identity for future generations
Beth Brady is the Senior Science and Conservation Associate at Save the Manatee Club whose work focuses on manatee biology and conservation. She has her PhD from Florida Atlantic University and her Master’s in Marine Science from Nova Southeastern University.
Marine Life & Conservation
Paul Watson Released as Denmark Blocks Japan’s Extradition Bid
Renowned anti-whaling activist Paul Watson has been released from custody in Greenland after spending five months in detention. Denmark’s Justice Ministry rejected Japan’s request for his extradition, citing insufficient guarantees that his time already served in custody would be credited against any potential sentence.
The 74-year-old Canadian-American was arrested on July 21 in Nuuk, Greenland’s capital, when his ship docked to refuel. His arrest was based on a 2012 Japanese warrant related to a 2010 encounter in Antarctic waters. Japan alleged Watson obstructed operations and caused damage to a whaling research ship during efforts to disrupt illegal whaling. Watson has consistently denied these claims, maintaining his commitment to marine conservation.
Denmark, which oversees extradition matters for Greenland, concluded that while the legal conditions for extradition were met, the lack of assurances from Japan regarding time-served credit made extradition untenable.
In a video shared by his foundation, Watson expressed gratitude and relief, saying, “After five months, it’s good to be out… and good to know they’re not sending me to Japan.” He added that the most difficult part of his time in custody was being separated from his two young sons.
Watson is a pioneering figure in marine conservation, known for founding the Captain Paul Watson Foundation in 2022 after decades of activism with the Sea Shepherd Conservation Society. His bold efforts to defend marine life have earned him widespread support, including from celebrities and conservationists. His work has also been featured in the acclaimed reality TV series Whale Wars.
Watson’s lawyer, Jonas Christoffersen, praised the decision, stating, “We are happy and relieved that Paul Watson is now free.” He added that Watson is eager to reunite with his family and continue his vital work.
The arrest occurred while Watson’s vessel, the M/Y John Paul DeJoria, was en route to the North Pacific with a team of 26 volunteers to intercept a Japanese whaling ship. His foundation described the arrest as politically motivated and emphasized that Watson’s actions were focused on ending illegal whaling practices.
Japan resumed commercial whaling in 2019 after leaving the International Whaling Commission, asserting that whale meat is a cultural tradition. Conservationists, however, continue to challenge these practices, highlighting their impact on marine ecosystems.
Despite the challenges, Watson remains steadfast in his mission to protect marine life and bring attention to whaling practices. His dedication to ocean conservation has made him a globally respected advocate for the environment.
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