▲ In an expedition last summer , Scripps scientists used the remotely operated vehicle , SuBastian , to collect sediment push cores near discarded barrels on the seafloor .
marine mammals . In 2015 , a study from Scripps chemical oceanographer Lihini Aluwihare and her then-PhD student , Nellie Shaul , co-authored a study that showed extremely elevated levels of DDT in dolphin blubber . And in 2020 , the Marine Mammal Center reported cancer affecting nearly 1 in 4 adult sea lions along the California coast .
“ The extent of the dumping ground being uncovered helps explain the high body burden of DDT we ’ ve seen in top predators in Southern California waters ,” says Aluwihare . “ It appears to be entering the water column food web from the seafloor , but how this is happening remains to be explored . Given the multi-generational impacts of DDT , we need to study this to understand the health of the ecosystem and seafood we consume .”
Last summer , Aluwihare visited the dumpsite that Terrill had surveyed earlier to collect organisms that live at depths greater than 650 feet . Along with Scripps biological oceanographer Anela Choy , the team will investigate which organisms may be transferring DDT from the seafloor up through the marine food web . Scientists also hope to look at Scripps ’ decades-old archive of marine specimens to see when DDT concentrations began appearing .
In a separate summer research expedition , Scripps scientists Lisa Levin , PhD ’ 82 , Paul Jensen , PhD ’ 06 , and Greg Rouse collected marine specimens and sediment samples near six barrels . Sponges and other invertebrates living on barrels were slurped up by a deep sea robot , as were samples of microbial halos , bearing eerie resemblance to fried eggs . They hope to evaluate these specimens to determine what role microbes might play in potentially bioremediating , or consuming , the chemicals coming out of the barrels .
“ Understanding the scope of the problem is the first step to determining a solution ,” says Terrill . “ The mapping of one of the dumpsite is just a start , but we still have a lot to science to do .”
Learn more and support UC San Diego ’ s efforts to understand the impacts of the dumpsite at : tritonmag . com / ddt
It ’ s not all trouble beneath the surface . Here are some promising Scripps discoveries from the deep :
DRUG DISCOVERY : An anti-cancer drug derived from a deep-sea ocean microbe is headed toward public use . Collected from tropical Atlantic Ocean sediment by researchers Bill Fenical and Paul Jensen , PhD ’ 06 , a compound produced by the microbe is nearing final tests for treating brain cancer glioblastoma . tritonmag . com / seadrug
UNDERWATER RECOVERY : Using historical data , sonar and autonomous underwater vehicles , a team led by Scripps researcher Eric Terrill ’ 93 , PhD ’ 98 , and underwater archaeologist Andrew Pietruszka recently recovered the remains of U . S . Air Force Maj . Paul A . Avolese , whose aircraft crashed during the Vietnam War . The effort was part of Project Recover , a partnership to find the resting places of missing American soldiers . tritonmag . com / recover
CLIMATE AUGURY : Though not currently underwater , an ancient mangrove ecosystem in the Yucatán was found flourishing more than 124 miles from the coast . While typically found in marshlands , these inland mangroves suggest that Gulf of Mexico coastal lowlands were underwater during the last interglacial period 125,000 years ago . These findings may yield better models of future sea-level fluctuations . tritonmag . com / mangroves
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