Human Influences on Coastal Zones

What are the most significant impacts we have on coastal regions?

What are the facts?What can be done?

Under the Sea…

Five Key Concerns

Overharvesting of Fisheries

Habitat Degradation and Destruction

Pollution

Global Climate Change

Human Population Growth

Overharvesting of fisheries resources

Many stocks in our region have been overharvested and are on the point of commercial extinction. Some are even in danger of complete extinction.

Honest error, local and international politics, greed, and mismanagement all play a role.

Thousands of fishers and fish-plant workers have been put out of work. Workers in related industries, such as shipbuilding and maintenance, fishing gear manufacturing, trucking, wholesaling, warehousing, etc., have also suffered.

Economic repercussions spread throughout affected communities or regions. Can you think of other examples?

Port aux Basques Problems

The attention of fishing fleets has shifted to other, usually smaller, species - often at a lower trophic level in the marine food web.

In addition to potentially harming the new “victim,” this practice can slow down or prevent the recovery of the larger fish – as they face a dwindling food source…

The overfishing of one fish stock can also have negative effects on apparently unrelated species.

For example, depletion of cod stocks = a large population of seals looking for alternative food sources = a negative effect on wild Atlantic salmon populations.

Habitat Degradation and Destruction (Physical)

Filling in wetlands; removal of sand and gravel from shore areas; building piers, houses, and industrial parks; and so on, clearly destroys or degrades the habitat.

Siltation of marshes due to agricultural and forestry practices further upstream clearly degrades habitat.

Dunes

Invisible habitat degradation and destruction: damage done to the seafloor by draggers. This has been compared to similar damage done by clear-cutting of forests.

It too is thought to be partially responsible for the slow recovery rates of groundfish stocks. The benthic micro-environment that larval groundfish require in order to thrive has been essentially bulldozed.

Pollution

Marine pollution is defined as the release into the ocean by humans of substances or energy that change the quality of the water and affect the physical and biological environment.

Main categories: Untreated human sewage with

disease-causing micro-organisms

Mineral nutrients that provoke phytoplankton growth (such as excess nitrogen)

Toxic wastes originating from industrial processes and disposed of in wastewater

China Water

Runoff from terrestrial sources, including

– fecal residue from livestock– pesticides, herbicides, and fertilizers– petroleum products leaking from

vehicles and being washed into storm drains by precipitation

– road salt– metals leached from soils by acid

precipitation and through industrial wastes… (Why do swordfish contain unacceptably high levels of mercury?)

Seaborne effluent from ships and pleasure craft:

– oil leakage falling into two categories

(1)catastrophic oil spills (Exxon Valdez, etc.)

(2)chronic leakage of small volumes from ship engines, emptying of ballast tanks and clearing of bilges

– sewage and garbage from ships

Global Climate ChangeThe effects of global climate change are

difficult to predict. Precipitation patterns may change. Some areas may get a little warmer, others a lot warmer, while some may cool.

For example, one of the factors thought to be responsible for the collapse of the northern cod stocks so severely was a drop in water temperature near the bottom. It is suspected that cold dense water from melting ice is sinking to the bottom and actually cooling the bottom water to temperatures that are sub-optimal for northern cod.

Rising sea levels caused by– melting of icecaps– expansion of ocean water due to a

rise in its average temperature• changes in current directions and

flow rates• increased incidence and severity of

storms• increased storm damage caused by

the combination of rising sea level and higher storm surges produced by severe storms

Human Population Growth

The increasing number and density of humans in coastal and inland areas is intensifying all the problems listed above. More people require more space and resources and create more wastes of all kinds.

Increased use by humans degrades the coastal zone environment. The degradation of the coastal zone reduces its ability to sustain humans and their economic activities.

So……What can we do?

Ticket To Leave: In one of the following ways - short essay, pictorial figure, brochure or chart/graph -

Pick one of the above key concerns and illustrate the human influence on the coastal environment. Include 3 things we can do to help lessen the impact.

Example

1. Further education regarding forms of Birth Control2. Controlled Emigration and Immiration