Unsustainable fishing methods refers to the utilization of the various fishing methods in order to capture or harvest fish at a rate which sees the declining of fish populations over time. These methods are observed to facilitate the destructive fishing practices that destroy ecosystems within the ocean, and is used as a tool for over-fishing which results in the depletion of fish populations at a rate that cannot be sustained. These unsustainable fishing methods vary in capabilities, ranging from commercial-grade equipment, such as bottom trawling, to consumer-grade equipment, such as fishing rods and nets. It is the combination of these methods and increasing fishing pressures through sociological practices such as over-exploitation and over-fishing, which makes these fishing methods unsustainable. Defining unsustainable The unsustainable nature of fisheries can be characterized by three aspects, as stated by Ray Hilborn: Inconsistent long-term yield refers to the imbalance in nature when fishing is practised improperly, which results in the inability to capture the maximum sustainable yield at a regular and predictable rate. Endangering intergenerational equity relates to the destruction of ecosystems that requires more than one generation to reverse, disallowing future generations the opportunity to capture that same yield. Destroying a biological, social, and economic system priorities the health of the human ecosystem or livelihood over that of the ocean's biodiversity, where the depletion of individual stock is carried out until the ecosystem's intrinsic integrity is lost. Types of unsustainable fishing methods Bottom trawling Bottom trawling is classified as an active gear that consists of a large weighted net, which trawls or "drags" along the sea floor; acting as a destructive mechanism that removes coral and other marine species. As stated by the Sea Fish Industry Authority, the trawl consists of several components that assist the catch composition of the gear, which includes: The otter boards which herd the fish into the trawl path by dragging up a "sand cloud" that creates a barrier of escape. The sweeps and bridles continue to herd the fish further into the trawl. The wings and ground gear minimize the potential for fish to escape, which also tires the fish and enables them to drop into the body of the net. Bottom trawling is scientifically divided into two types of trawling, demersal trawling and benthic trawling, which allows trawlers to target species that live close to the seabed, or those that live on or in the seabed respectively.