These are some of the current issues that will require the most attention in the future if we are to sustain our fisheries. Maybe you can think of ways to help solve some of the problems in your area?

HABITAT LOSS

Marine organisms, like humans, depend on habitats, or homes. Fish rely on a variety of habitats for spawning, breeding, and growth. Like any living organism, without a healthy habitat, fish cannot survive. Human activities, however have been degrading and destroying fish habitat worldwide. Some of the activities that can be harmful to fish habitat include pollution, dredging, anchors from boats, trampling, the building of docks, oil drilling platforms, etc. As a result, today’s world fisheries are less productive than in the past. Certain species have become rare finds, and overall marine biodiversity is declining.
Most habitat loss in British Columbia occurs in estuaries and nearshore areas, but deeper areas can also be affected by ocean dumping. A primary concern in BC is the degradation and loss of eelgrass habitat, which is important for numerous fish and shellfish species as part of their life cycles. Surprisingly little is known about essential fish habitat in the ocean. Even less is known about how we impact those habitats and ultimately what affect this has on the fish populations. The bottom of the ocean is hidden from view to us. Can you imagine what it looks like down there?

What do you know about the little fish?
About 75% of commercially important fish in North America use estuaries for at least one stage in their life cycle – often the critical, early stages of life.

OVER-FISHING

Overfishing is very simple … taking too many fish. When a stock of fish is overfished, it means that more fish are taken from the population than can be replaced by natural reproduction. The United Nations believes that almost every commercially important species around the world is over-fished. Overfishing one species can have a big effect on many other species in the ecosystem. For example, the overfishing of the small fish herring, has had an effect on many of the herring’s predators such as salmon and sea lions.
Another important part of understanding overfishing is something called over capacity. Over capacity is the idea that there are “too many people chasing too few fish”. Over capacity in fishing is made worse by the large-scale mechanization and industrialization of the fishing industry. Our technology is simply too good! This means that an area can become overfished pretty fast. Today, 70% of the planet’s major marine fisheries are fully exploited or over exploited.
In some parts of the world people have taken action to prevent fishing communities from being pushed out by large-scale industrial fishing. In 1994, a million fish workers in India went on strike. They were worried that large international boats would overfish coastal areas and mean a lack of fish for local people. Also, in Indonesia there is a ban on large-scale fishing in all nearshore areas. This ban helps to preserve fish as a source of food and jobs for local communities.

POLLUTION

While the water quality along Canada’s Pacific coast is generally considered to be quite good, there are many areas for concern. Sources of pollution may include industrial and municipal wastewater, agricultural runoff, dumped materials, and oil and chemical spills. One indicator of water quality - the number of beaches closed to clam harvesting- has risen along the BC coast to about 160 closures per year. Coastal pollution of sewage or fertilizers in runoff often result in too many nutrients in the water, this is called eutrophication. These excess nutrients can cause blooms of algae that are sometimes toxic and deplete the oxygen in the water, killing many marine animals.

INTRODUCED SPECIES

The introduction of foreign or exotic species has changed many coastal and ocean ecosystems. Often, these introduced species are able to outcompete native species for food and habitat. Rocky shorelines in the Strait of Georgia are often covered in introduced oysters, and some of the more common clams - the manila and varnish clam - have also been introduced. While some of these introductions happened many years ago, others are still happening. A recent example is the northward expansion of the Green crab into BC. The Green crab (Carcinus meanus) is a species from Europe that has invaded both coasts of North America. They think it came here in the ballast water of a ship. It has been on the West Coast only for about twenty years and has spread from California up to BC. The problem with this crab is its appetite. Scientists and fishers are worried that it might be a bigger eater than our local shore crabs and take over their habitats. The Green crab likes to eat baby shellfish, like oysters and clams. This could also be a problem…especially for the people who grow oysters and clams for a living.

GLOBAL CLIMATE CHANGE

The global climate is changing, and that means the environment is too. Global warming may be affecting not only the temperature of the ocean, but also the patterns of large oceanic currents, the location of upwelling zones created by those currents, and therefore all the organisms that live in the oceans. An upwelling zone is an area where cold water rises up from the deep ocean bringing with it lots of food and nutrients that are the basis for a rich marine ecosystem.
Global warming is accelerated by an increase of greenhouse gasses in the atomosphere, especially carbon dioxide. The concentration of carbon dioxide in the atmosphere has increased by 30 percent since the beginning of the Industrial Revolution. The best (and cautious) predictions forecast a global temperature increase of between 1 and 4 degrees celcius and a rise in sea level of 10 cm to 100cm over the next century (Lubchenco). There are some marine species, such as salmon, that are very sensitive to even small changes in water temperatures. During the past 1997/98 El Nino event, species usually found only in warmer waters, like mackerel, migrated northward into B.C.’s waters, where in many cases they consumed large numbers of local species.

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