What Are the Major Threats to Aquatic Biodiversity?

Aquatic Biodiversity

• Greatest marine biodiversity

  • Coral reefs

  • Estuaries

  • Deep-ocean floor

• Biodiversity is higher

  • Near the coast than in the open sea

  • In the bottom region of the ocean the surface region

Natural Capital: Marine Ecosystems

• Ecological Services

  • Climate moderation

  • CO2 absorption

  • Nutrient cycling

  • Waste treatment

  • Reduced storm impact

  • Nursery areas

  • Scientific information

• Economic Services

  • Food

  • Animal and pet feed

  • Pharmaceuticals

  • Harbors and transportation routes

  • Coastal habitats for humans

  • Recreation

  • Employment

  • Oil and natural gas

  • Minerals

  • Building materials

Natural Capital: Freshwater Systems

• Ecological Services

  • Climate moderations

  • Nutrients cycling

  • Waste treatment

  • Flood control

  • Groundwater recharge

  • Habitats for many species

  • Genetic resources and biodiversity

  • Specific information

• Economic Services

  • Food

  • Drinking water

  • Irrigation water

  • Hydroelectricity

  • Transportation corridors

  • Recreation

  • Employment

Human Activities Are Destroying and Degrading Aquatic Habitats

• Marine

  • Coral reefs

  • Mangrove forests

  • Seagrass beds

  • Sea-level rise from global warming will harm coral reefs and low-lying islands with mangrove forests

  • Ocean floor

    • effect of trawlers

• Freshwater

  • Dams

  • Excessive water withdrawal

Invasive Species Are Degrading Aquatic Biodiversity

• Invasive species: Threaten native species and disrupt and degrade whole ecosystems

Population Growth and Pollution Can Reduce Aquatic Biodiversity

• More noise and crowding from humans

• Nitrates and phosphates, mainly from fertilizers, enter the water

  • Leads to eutrophication

• Toxic pollutants from industrial and urban areas

• Plastics

Overfishing and Extinction: Gone Fishing, Fish Gone

• Fishery: concentration of a particular wild aquatic species suitable for commercial harvesting in a specific area

• Fish print: area of ocean needed to sustain the fish consumption of a person, country, or the world

• Marine and freshwater fish: Threatened with extinction by human activities more than any other group of species

• Commercial extinction: no longer economically feasible to harvest a species

How Can We Protect and Sustain Marine Biodiversity?

Legal Protection of Some Endangered and Threatened Marine Species

• 1975 Convention on International Trade in Endangered Species: An international convention that combines wildlife and trade themes with a legally binding instrument for achieving conservation and sustainable use objectives

• 1979 Global Treaty on Migratory Species: Builds global conservation efforts on all migratory species.

• U.S. Endangered Species Act of 1973: Protects critically imperiled species, damaged by development and economic growth from extinction

• U.S. Whale Conservation and Protection Act of 1976: Regulates the Secretary of Commerce to undertake comprehensive conservation studies of all whales found in US waters

• 1995 International Convention on Biological Diversity: Links traditional conservation efforts to the economic goal of using biological resources sustainably

Marine Sanctuaries Protect Ecosystems and Species

• Offshore fishing→ Exclusive economic zones for countries

  • 200 nautical miles

• High seas are governed by treaties that are hard to enforce

• Law of the Sea Treaty

  • Misused

• Marine protected areas (MPAs): Protected from human activities

Establishing a Global Network of Marine Reserves: An Ecosystem Approach

• Marine reserves

  • Closed to

    • Commercial fishing

    • Dredging

    • Mining and waste disposal

  • Core zone: No human activity allowed

  • Less harmful activities allowed

    • E.g., recreational boating and shipping

How Should We Manage and Sustain Marine Fisheries?

Estimating and Monitoring Fishery Populations Is the First Step

• Maximum sustained yield (MSY)

  • the traditional approach

• Optimum sustained yield (OSY)

• Multispecies management

• Large marine systems

  • using large complex computer models

• Precautionary principle

Consumer Choices Can Help to Sustain Fisheries and Aquatic Biodiversity

• Need labels to inform consumers how and where fish was caught

• 1999- Marine Stewardship Council (MSC): Certifies sustainably produced seafood

• Proper use of sustainable aquaculture

  • Plant-eating fish best --Tilapia

Solutions to Managing Fisheries

• Fishery Regulations

  • Set low catch limits and improve monitoring and enforcement.

• Economic approaches

  • Reduce or eliminate fishing subsidies

• Protect Areas

  • Establish no-fishing areas and establish more marine-protected areas

• Consumer Information: Label sustainably harvested fish and publicize overfished and threatened species

• Bycatch: Use nets that allow the escape of smaller fish

How Should We Protect and Sustain Wetlands?

We Can Preserve and Restore Wetlands

• Laws for protection: Zoning laws steer development away from wetlands. In the U.S., one needs a federal permit to fill wetlands greater than 3 acres

• Mitigation banking: Can destroy wetlands if create one of equal area.

Managing River Basins Is Complex and Controversial

• Columbia River

  • U.S. and Canada

• Snake River

  • Washington state, U.S.

• Dams: Provide hydroelectric power, provide irrigation water, and hurt salmon

Natural Capital: Ecological Services of Rivers

• Deliver nutrients to sea to help sustain coastal fisheries

• Deposit silt that maintains deltas

• Purify water

• Renew and renourish wetlands

• Provide habitats for wildlife

What Are the Priorities for Sustained Biodiversity, and Ecosystem Services?

Using an Ecosystem Approach to Sustaining Aquatic Biodiversity

• Edward O. Wilson: Completed the mapping of the world’s aquatic biodiversity, identified and preserved aquatic diversity hotspots, created large and fully protected marine reserves, protected and restored the world’s lakes and rivers, and ecological restoration projects worldwide.