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Entries in fish science (90)

Monday
Feb022015

850 kilometers from sunlight 

Credit: Reed Scherer (NIU)

Stunned researchers in Antarctica have discovered fish and other aquatic animals living in perpetual darkness and cold, beneath a roof of ice 740 meters thick. The animals inhabit a wedge of seawater only 10 meters deep, sealed between the ice above and a barren, rocky seafloor below—a location so remote and hostile the many scientists expected to find nothing but scant microbial life.

LINK (via: Scientific American)

 

Monday
Jan262015

Fish Mission Kiritimati Part 2

Here is an overview from Dr. Andy Danylchuk as his team embarks on an upcoming research trip to Kiritimati.

In 2014 a research trip to Kiritimati quickly changed focus from bonefish to giant trevally (GTs).  This switch was prompted by a growing emphasis for targeting GTs and conservation concerns raised by stakeholders. During that trip, research was conducted to begin examining the physical and physiological impacts of angling with the intention of using the results to begin building best practices for the catch-and-release of GTs, not only for Kiritimati, but also throughout their range.  This is critical since the popularity of GTs is increasing as evident by posts on social media, launching of angler groups specifically targeting GTs, and articles in conventional popular media outlets.

We're now headed back to Kiritmati with larger team of researchers to undertake a much more directed study on GTs.  Specifically, we will be looking at the degree of physical injury caused by baits commonly used for GTs. We will examine different hook types and configurations to systematically determine the bait type that minimized physical injury without significantly reducing hook ups.  We will also be continuing to examine the physiological stresses associated with angling through the use of non-lethal blood sampling and on-site blood processing.  This will allow us to determine whether there is a direct relationship between parameters such as angling time and physiological stress.  The outcome of this component will be best practices linked to selecting tackle and techniques allow anglers to bring GTs to the boat without ‘maxing’ them out physiologically.  One specific element of the angling event we will be testing is the impacts of air exposure.

The last component of the GT work will involve the use of custom data logging devices that will pop-up of the fish following a short duration of time following releases.  These pop-up data loggers will collect depth and activity patterns related to swimming performance – something that can vary related to the degree of handling stress.  Acoustic transmitters in the pop-up device will allow us to manually track the fish following release and then locate the device once it is floating at the surface.  Although this element of the project will be challenging, it will net the first ever data on the short term activity patterns of GTs plus it will lead to a more robust set of best practices for this now highly prized fish species.

Thursday
Jan152015

Recycling Rare Earth Metals With, Yes, Fish Sperm

Photo:Rajesh dangi

If you're not up on your fish-cum-metal news, then you might be forgiven for finding the idea of using fish sperm to recycle rare earth elements entirely bizarre.

LINK (via: Gizmodo)

Monday
Jan122015

What do you call a fish without an eye?

Fsh....

Vancouver Aquarium head veterinarian Dr. Martin Haulena, with help from Dr. Lesanna Lahner of Seattle Aquarium, affixes a prosthetic eye on a yellowtail rockfish (Sebastes flavidus) that had its eye removed due to cataracts. They performed the same surgery on a second rockfish, a copper rockfish (Sebastes caurinus), seen at the end of this video. The purpose of this procedure is partly cosmetic and partly for the fish’s welfare. Without an eye, the other fishes would act aggressively towards it for seeming sick and weak.

(via: Scientific American)

Sunday
Jan112015

New Model Identifies Perfect Habitat for Brook Trout

A new model that can accurately identify stream sections that still hold suitable habitat for wild brook trout will help fisheries managers from Maine to Georgia find and protect habitat for this fish, which is an economically, socially and ecologically important species.

LINK (via: The Fish Site)

Monday
Jan052015

AFS Hatchery vs. Wild Symposium 

Key word here is reform.

The Oregon Chapter of the American Fisheries Society is sponsoring the Hatchery vs. Wild Salmonid Symposium – Research, Management, and Reform in the Pacific Northwest, January 22-23, 2015, at the Hilton Portland in downtown Portland, Oregon.

LINK (via: Osprey Steelhead News)