source : Dr Peter Moyle Marinebio.org
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Habitat conservation for wild species is one of the most important issues facing the environment today - both in the ocean and on land. As human populations increase, land use increases, and wild species have smaller spaces to call home. More than half of Earth's terrestrial surface has been altered due to human activity, resulting in drastic deforestation, erosion and loss of topsoil, biodiversity loss, and extinction. Species cannot survive outside of their natural habitat without human intervention, such as the habitats found in a zoo or aquarium for example. Preserving habitats is essential to preserving biodiversity. Migratory species are particularly vulnerable to habitat destruction because they tend to inhabit more than one natural habitat. This creates the need to not only preserve the two habitats for migratory species, but also their migratory route. Altering a natural habitat even slightly can result in a domino effect that harms the entire ecosystem. The following is an example illustrating this point by Dr. Peter Moyle:
"Habitats don't exist in isolation; most of them have inputs and outputs connected to other habitats and ecosystems. Take Mono Lake, for instance, a spectacular lake on the east side of the Sierra Nevada in California. Its water source is streams fed by winter rains and melting snow in the mountains. In its natural state, water leaves the lake only by evaporation. The balance between the inflowing streams and evaporation created a saline lake with many unique features, including a species of brine shrimp found only in Mono Lake. As a large, food-rich body of water in a desert area, the lake is a major fueling stop for migratory waterbirds and a major nesting area for other species, such as California gulls. When water from the lake's inflowing streams was diverted to quench the ever-growing thirst of southern California, the lake level dropped drastically. Islands in the lake became connected to the mainland, giving coyotes and other predators access to an easy source of food: nesting California gulls. With adequate inflowing water, the islands were good nesting habitat; without the water they were unsuitable as nesting habitat. Without adequate inflowing water, the lake also would become too saline for the Mono brine shrimp to survive and for migratory waterbirds to feed in. Recognition of this fundamental relationship between inflow and habitat for many species was the partial basis of a successful court action that reduced the diversion of water from the inflowing streams."
Habitat destruction is a huge problem in the marine environment. Habitats are destroyed by:
Destructive fishing activity: bottom trawling and dynamiting coral reefs destroy entire ecosystems.
Coastal development: habitats are destroyed when marshes are dredged for real estate development. Soil runoff and erosion result in excess nutrients from fertilizers and domestic sewage, which then leads to harmful algae blooms that block sunlight and deplete the water of oxygen. It also causes silt to build-up on coral reefs, which blocks sunlight necessary for coral to grow.
Pollution: development near coastal waters contaminates the Ocean with toxic substances, such as industrial chemicals, pesticides, and motor oil.
Dredging ship channels: Removes accumulated sediment and pollutants re-suspending them into the water. Dredging can also destroy sea grass beds and other habitats that provide food, shelter, and breeding grounds. The dredged material must be disposed of, and is often dumped into salt marshes damaging a very productive marine habitat.
Marine Protected Areas (MPAs): marine sites such as sanctuaries, fisheries management areas, state conservation areas, and wildlife refuges established to protect habitats, endangered species, and to restore the health of marine ecosystems in areas jeopardized by habitat and species loss.
Examples: NOAA National Marine Sanctuaries: USA
Marine Reserves: marine sites that provide a higher degree of ecosystem protection by prohibiting fishing, mineral extraction, and other habitat-altering activities. Marine Reserves are far more effective than MPAs, but unfortunately they are not as common.
See: Roberts, C.M. and J.P. Hawkins. 2000. Fully-protected marine reserves: a guide. (PDF: 6.62MB) WWF Endangered Seas Campaign, 1250 24th Street, NW, Washington, DC 20037, USA and Environment Department, University of York, York, YO10 5DD, UK.
Example: Marine Reserves in New Zealand
Land use and development regulation: An integrated approach to land use and management based on scientific knowledge is needed to protect coastal areas. Policy makers need to be informed on the impact coastal development is having on marine habitats through accessible and evidence-based information.
Monitoring and reporting: some conservation efforts are empowering the citizens with the responsibility for monitoring water quality in their coastal communities through sampling and testing, photographing fouled areas, and providing information to local policy makers for action.
Zoning: related to integrated land use and development management, zoning coastal areas into MPAs, Marine Reserves, approved fishing areas, with varying levels of use has the potential to slow some of the habitat degradation caused by development. The Great Barrier Reef is managed in this way. Through cooperation among local, state, and national governments, this approach may provide a viable solution to all stakeholders from tourists, to the fishing industry, to conservation efforts etc.
Although habitat destruction has been increasing for many years, the protection of marine habitats has only recently become an issue of critical importance to conservation efforts, local and national governments, and international marine conservation groups. The Ocean's invulnerability to human activity is now being realized as a myth. Coastal regions are still experiencing intense pressure by exploding coastal populations; however there are solutions at hand to prevent further damage from occurring.
Everyone knows that the Northern Spotted Owl is threatened because of destruction to the forests of the Pacific Northwest - but what will happen to the Pacific Seahorse if its habitat continues to decline? Due to the lack of a strong public sea ethic marine life doesn't appear on the conservation radar screen as much as its terrestrial counterparts, but ocean habitats are in decline as well, and therefore the creatures they support are too (which in turn support us). Most marine habitat destruction is caused by pollution, commercial fishing equipment, coastal development, and other human activity. Much of it can be avoided with simple measures.
Chapter 7: Niche and habitat - Essays on Wildlife Conservation, by Dr. Moyle, University of California, Davis
» How is your Marine Protected Area (MPA) doing?
A Guidebook of Natural and Social Indicators for Evaluating Marine Protected Area Management Effectiveness (PDF, 234 pg, 3MB)
"The challenge of establishing a representative system of marine protected areas (MPAs) is surpassed by the challenge that they are managed effectively over time. There is a long way to go in achieving this goal, with less than 1% of the world’s ocean declared under marine protected areas and fewer than 10% of marine protected areas that exist today achieving their management goals and objectives (Kelleher et al., 1995). Ultimately, it is only by assuring their effective management that MPAs can contribute to the ambitious overarching goals of biodiversity conservation, sustainable use of marine resources, and an improved quality of life for coastal communities."
It does seem that the USA, New Zealand and Australia are a long way ahead of the UK in the establishment of Marine Reserves and their management. In common with the Marine Conservation Society, we believe that the introduction of the Marine Bill is way overdue.