[ad_1]
Jane Watson has studied sea otters for decades, but in the 1990s an ecologist in British Columbia observed that they have a destructive habit. While conservationists were working diligently to repair damaged seagrass meadows elsewhere in the world’s oceans, it seemed ironic that in the seagrass habitat of north Vancouver Island, which is much healthier than any other in the world, hairy swimmers would come in and dig up oysters. water displaces vegetation.
While he and others surveyed the sandy bottoms marked by mussel digging pits, Dr. Watson noted anecdotally that grasses, also known as eels, bloom more frequently where otter populations are well established.
He wondered: Did these destructive otters affect plant reproduction? He sat on the idea for years, but his curiosity later inspired one of his undergraduate students at Vancouver Island University. Years later, this hunch was proven correct. An article published Thursday in the journal Science and is led by Erin Foster, a former student who is now a research fellow at the Hakai Institute.
Dr. Research by Foster and colleagues shows that sea otters are like eel elephants. Their disturbance while digging oysters and dislodging eel roots stimulates sexual reproduction among vegetation. This sexual activity, in contrast to reproduction by natural cloning, increases eel genetic diversity and increases the resilience of ecosystems in which both otters and eels live.
The findings highlight the importance of restoring lost predators such as sea otters to marine ecosystems, whose diet has cascading effects throughout the environment.
Mary O’Connor, a seagrass ecologist not involved in the study at the University of British Columbia’s Center for Biodiversity Research, commended the research, saying that the genetic effects of large predators on other parts of ecosystems are understood in ecological theory.
Dr. Foster says the Eelgrass has two breeding forms. It can reproduce asexually by cloning from roots. Or gentian can reproduce sexually, producing flowers that pollinate and produce seeds. Sexual reproduction that produces unique combinations between different plants is like playing the genetic lottery. Cloning, by contrast, makes each offspring genetically identical.
Therefore, while pursuing his PhD at Victoria University, Dr. Foster devised a complex test to see if sea otters affect eel reproduction. Dr. Collaborating with Watson and 11 other ecologists, evolutionary biologists and geneticists, Dr. Foster looked for eel genetic signatures by taking plant tissue samples from three species sites off the coast of the Great Bear Rainforest and West Vancouver Island.
In some areas, sea otters, a long-term effect of the European fur trade, were absent for more than a century. In others, reintroduced otters have existed for decades. And in a third subset of survey sites, otters have been present for less than 10 years. Meticulously collecting eel shoots for DNA analysis, Dr. Foster predicted that eel meadows with prolonged otter presence should have higher levels of genetic diversity.
He also tested the effects of latitude, depth, meadow size and temperature. But he found that the most influential factor for eel genetic diversity was the length of sea otter occupancy time. Sea otter digging has increased seedlings’ germination opportunities and increased eel genetic diversity by up to 30 percent.
The team notes that otters are not the only driving force behind eelgrass genetic diversity. In the past, eelgrass flowering may have been promoted by now-extinct or rare megafauna or Native traditional eelgrass harvesting. rhizomes and seeds, a practice that declined with European colonization.
Provides seagrass meadows rich food and protective habitats for marine life all over the world. The seagrass patches that support otters are unusually intact on these remote shores of British Columbia, but elsewhere, many are threatened by agricultural runoff, boating, and coastal development. By better understanding the factors that could make this life-supporting undersea carpet genetically healthier, this sea otter research “shows another way to hedge our bets on a predator,” said study co-author Chris Darimont, also at the Hakai Institute. against an uncertain future.”
[ad_2]
Source link