Oceanic “dead zones” a major concern for fisheries industry

By Jillianne Hamilton

            Dead zones in the ocean will have a major impact on the fisheries industry, says an aquaculture student.

            Trisha Lewis, 20, is a student at the Nova Scotia Agricultural College in Truro and the daughter of a Five Islands fisherman.

            Oceanic dead zones are caused by human-made chemicals, like certain fertilizers, entering the water systems. These particular ocean areas are low in oxygen and have become inhabitable by many species of fish.

            All living species need oxygen to live, said Lewis.

“When there is a lack of oxygen, living species may no longer be supported. In areas where there is a decreased oxygen, many fish may be faced with hypoxia.”

Hypoxia is a lack of oxygen in the fish's tissues. This can be lethal if the species doesn't find a way to get the oxygen it needs, she said.

“Hypoxia can lead to death very quickly and it is very stressful for the fish, which means the immune system will also become weak and the fish will be more succeptible to disease.”

The oceans are affected by a decrease in fish and also an increase in organic matter settling on the bottom of the areas with decreased oxygen.

“If dead zones are created, many aquatic species will no longer be able to live in those areas and be forced to go to other areas of the ocean which do have an adequate supply of oxygen,” Lewis said.

These dead zones can have a huge impact on the fishing industry if something isn’t done soon, she said.

“Since these dead zones are usually along coastal areas, fish will begin to move into deeper waters.”

Many people fish for recreation along the coast and many fish for a living, she said.

“If the fish are forced to move, the fishermen may see a decrease in their catch which directly affects their pocket book as well as the supply of fish for people to eat.”

Central Northumberland Strait Fisherman’s Association president Mike McGeoghegan is troubled by the issue.

“It is a concern,” he said.

McGeoghegan, a commercial lobster and crab fisherman, said it doesn’t take much to upset the environmental balance.

“The ecosystem is very fragile.”

However, he’s skeptical about these types of reports and the science community.

“Our voices are not heard very well,” he said.

These dead zones – and other oceanic anomalies – could be better understood by the scientific community by working closer with people who are impacted by them most, he said.

“When you’ve been out on the water, you learn a few things.”