Home | Contact ST  

Content on this page requires a newer version of Adobe Flash Player.

Get Adobe Flash player

Follow ST

Ocean Research

2018:  FEB

October 2017 Issue

Microplastics Transportable
To Deep Seafloor via Fecal Pellets

Over the last decade, scientists have discovered tiny pieces of plastic in many ocean waters and even in deep-sea mud. However, they know very little about how microplastics are transported within the ocean. A new MBARI study shows that filter-feeding animals called giant larvaceans can collect and consume microplastic particles in the deep sea. The particles accumulate in larvaceans’ cast-off filters and are passed into the animals’ fecal pellets, which sink rapidly through the ocean, potentially carrying microplastics to the deep seafloor.

Microplastics that reach the depths are likely to be ingested by deep-seafloor animals.

US Navy WWII Vessel
Wreckage Found in Pacific

Wreckage from the USS Indianapolis was discovered in August by the expedition crew of RV Petrel, which is owned by Microsoft co-founder and philanthropist Paul G. Allen. The Indianapolis was found 5,500 m below the surface, resting on the floor of the north Pacific Ocean.

The Indianapolis was torpedoed by a Japanese submarine July 30, 1945, in the final days of World War II. Prior to the attack, the Indianapolis had just completed its secret mission of delivering components of one of the two nuclear weapons that were dropped on Japan. Of the 1,196 sailors and Marines onboard, only 317 survived.

As the naval flagship of the Fifth Fleet, the sunken Indianapolis was the object of many previous search efforts. Allen had recently acquired and retrofitted the 250-ft. RV Petrel with subsea equipment capable of diving to 6,000 m. The 16-person expedition team on the vessel will continue the process of surveying the full site.

The USS Indianapolis’s location will remain confidential and restricted by the U.S. Navy.

UK Shelf Sea Biochem
Research for Sustainability

The coasts and shelf seas provide resources for food production, biodiversity, carbon cycling and storage, waste disposal, nutrient cycling, recreation and renewable energy. As more people move closer to the coast, these resources are degrading due to overfishing, pollution, habitat disturbance and climate change. There is an urgent need to understand the relative sensitivities of a range of shelf habitats so that human pressures can be managed more effectively to ensure long-term sustainability of the seas.

NERC and Defra initiated the Shelf Sea Biogeochemistry program (2011 to 2017) to document the sensitivity and status of seabed habitats around the U.K. based on their physical condition, biological communities and nitrogen and carbon concentrations.

Emerging results are providing information on which areas of the U.K. seabed are most vulnerable to human activities and climate change, which will be of value to planners and policy makers.

Marine Reserves Support
Commercial Fisheries

Commercial fishermen may be able to catch more of the profitable fish they want with marine reserves than without them, according to a study led by the University of California, Davis.

Using marine reserves as a management tool could also help the recently rebounded West Coast groundfish fishery sustain itself, the study notes.

Marine reserves, which are closed to fishing and other extractive activities, can result in fishermen catching more of the fish they target while protecting the weaker fish that can be caught inadvertently by indiscriminate fishing gear.

The solution proposed in the study is to protect bycatch species inside a marine reserve’s boundaries.

LISST Instruments to Study
Water Optical Properties

MacArtney has secured an order for LISST instruments from University of Bergen, Norway. LISST submersible instruments are manufactured by Sequoia Scientific Inc. and help engineers, scientists and monitoring agencies reliably measure the concentration and size of sediment, plankton and oil droplets in any water body.

The order consists of the LISST instruments LISST-VSF and LISST-200X, to be used in the sea close to the Lofoten Islands in northern Norway for water optical-property studies. The order includes MacArtney deployment frames for both instruments.

Caspian Sea Evaporating
As Temperatures Rise

Earth’s largest inland body of water has been slowly evaporating for the past two decades due to rising temperatures associated with climate change, a new study finds.

Water levels in the Caspian Sea dropped nearly 7 cm per year from 1996 to 2015, or nearly 1.5 m total. The current Caspian Sea level is only about 1 m above the historic low level it reached in the late 1970s.

Increased evaporation over the Caspian Sea has been linked to increased surface air temperatures. According to the data from the study, the average yearly surface temperature over the Caspian Sea rose by about 1° C between the two time frames studied, 1979 to 1995 and 1996 to 2015. These rising temperatures are likely a result of climate change, according to the study’s authors.

Evaporation brought about by warming temperatures appears to be the primary cause of the current drop in sea level, and the decline will likely continue as the planet warms.

AZFP Supports Predator/Prey
Studies in British Columbia

Two Ph.D. candidates, Rhonda Reidy and Will Duguid, part of the Fisheries Ecology and Marine Conservation group, are conducting studies that couple the capabilities of ASL’s Acoustic Zooplankton Fish Profiler (AZFP) with predator telemetry and prey sampling to provide novel perspectives on predator/prey interactions in selected study regions in southern British Columbia (BC) in Canada. These projects examine fine-scale processes with large-scale implications for marine ecosystems.

Reidy’s study seeks to link humpback whale feeding behaviors to concurrent measurements of prey in southern BC waters. This will better inform fishery management decisions.

Duguid is examining how the interactions of tidal currents and abrupt topographic structure influence the feeding ecology of chinook and coho salmon juveniles at fine spatiotemporal scales.

2018:  FEB

-back to top-

Sea Technology is read worldwide in more than 115 countries by management, engineers, scientists and technical personnel working in industry, government and educational research institutions. Readers are involved with oceanographic research, fisheries management, offshore oil and gas exploration and production, undersea defense including antisubmarine warfare, ocean mining and commercial diving.