Tag Archives: ocean

From sea to table: a series of unfortunate events

With an abundance of local marine life within arm’s reach, Vancouver has endless seafood options varying from Pajos fish and chips to fresh oysters at the Blue Water Cafe! While enjoying this variety of seafood, have you ever wondered how these fish end up on your dinner plate?

Different fishing gear types are used depending on the size, weight, and location of the fish that is being caught.  Although all gear types impact the ocean to some extent, the degree of impact varies!

Image of Pajos fish and chips at the Steveston wharf. Image: are you gonna eat that

Uncovering the impacts

To learn about the global use of fishing gear types and its associated consequences, we reached out to Tim Cashion a research assistant at The Sea Around Us research initiative at the University of British Columbia.

The Sea Around Us research initiative previously reconstructed global annual catches; however, it did not account for small-scale fishing (fishing for survival) and discarding (unwanted catches thrown back into the ocean). Cashion and his team utilized this prior work as well as analysis of more recent fisheries annual reports to reconstruct a database that accounts for all global marine catches, including: industrial fishing (fishing for profit), small-scale fishing, landings (catches of fish brought back to ports), and discards.

The most common gear types

Bottom trawling – the most destructive but widely used industrial gear type -involves dragging a large net across the ocean floor. The nets are held open by steel poles which detach coral from the ocean floor. This is detrimental to fish because corals serve as essential habitats for spawning and protection from predators.

Conversely, purse seining involves setting a purse-like net into the ocean and pulling it closed to trap schools of fish! This method is less destructive and more effective as it catches up to 99% of the species that the gear is intended to catch.

A video of common fishing gear types used in small-scale and industrial fisheries:

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Video: wonderfulblossoms

Unintentional catch

Although fishing gears are skillfully constructed, they are not perfectly selective! For instance, bottom trawl nets catch every life form that it encounters. Consequently, fish of the wrong species are often caught and thrown back into the ocean in their dying state. If these perfectly good fish entered the market then the price of fish would be cheaper! Who doesn’t like to save money?

Image result for fishing damage

Image of a sea turtle entangled in a net. Image: Doug Helton

Importance of the reconstructed database

The reconstructed database allows fisheries scientists to evaluate the risk of overexploitation of some species. Furthermore, this information will help improve fisheries management and ensure that fish populations do not decline overtime due to fishing practices.

A podcast discussing the major impacts of fishing gear types is linked below.

By: Jack Bae, Sami Ko, Alex Ponomarev, and Jodie Xie

Microplastics: A Pollution Worse than Plastic?

Source: Providence Trade

As detrimental as this photo looks, today’s plastic pollution is unfortunately not limited to these plastic bags and bottles that line the ocean surfaces. Recently, plastic has begun to affect ecosystems and species in ways we did not ever imagine; in the form of microplastics.

What are Microplastics?

Microplastics are small, barely visible pieces of plastic that ultimately enter and pollute our oceans, streams, rivers, soil and air. They can enter our environment from a variety of sources including cosmetics, textiles and industrial settings, or simply from the plastics we pollute each day. According to a recent study done by researchers in Japan, the abundance of microplastics within the world’s oceans has raised growing concerns amongst environmentalists globally due to their detrimental effects on ecosystems and living organisms, including humans. Unfortunately, due to the small size of microplastics, ranging from 5mm to the diameter of a red blood cell, it is difficult to report the exact amount found in our oceans. Researchers estimate that with around 300 million metric tons of plastic produced each year, trillions of degraded plastic bits may be lurking in the environment, largely unseen.

Source: Andrea Thompson via Scientific American

Microplastics in our ecosystem and in our bodies:

Source: Dr. Marcus Eriksen of Gyres Institute

Since microplastics are, as the name suggests, microscopic, they can be ingested by a wide variety of creatures, including plankton (the basis of the marine food chain). Real harm can be done if microplastics in fish and other species move from their gut into the bloodstream and other organs. A study done by Mark Browne shows physical signs of damage, as the particles jabbing and rubbing against organ walls can cause inflammation, while leaching of hazardous chemicals cause liver damage. These hazards can disrupt the immune functions, growth and reproduction of organisms. Even if individual species do not seem to suffer, their ingestion of microplastics can have a ripple effect when they accumulate within a food chain, as another study shows how the fish do not necessarily excrete the microplastics once ingested.

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Not only are these microplastics found in wildlife species, according to a recent study, we actually ingest them everyday. In addition to being present in packaged food and bottled water they are found in tap water and even in the air we breathe, making it virtually impossible to avoid them.

According to Browne’s research, the amount of microplastics in lakes and soils alone could rival the more than 15 trillion tons of particles thought to be floating on the ocean surface. Before we can make any progress on curbing this pollution, we must first understand how much is concentrated in which places, where exactly it is coming from, and how it is moving around.

For more information listen to this interview done by Kate Nielson from the National Oceanic and Atmospheric Atmosphere:

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