Modern sea turtles are an important component of a wide range of tropical, temperate, and cold water marine ecosystems. Their inclusion on various lists of endangered species reflects past over-exploitation and the current need for better management. Today, seven or eight species of sea turtles are recognised, in two families and six genera. Adults typically migrate between resident foraging grounds and natal nesting beaches; females reproduce on one to nine year cycles, laying multiple clutches in a season, while males may breed more frequently. Hatching success is usually 80% or more unless external factors intervene. Immature sea turtles grow slowly and delayed maturity requires that large numbers of eggs, hatchlings, juveniles and subadults be maintained in a population in order to sustain even a relatively small number of reproductively active adults. Some populations of some species may take 30 to 50 years (or more) to reach adulthood. Sea turtle populations have survived and indeed flourished until very recent times. Today they are classed as Critically Endangered, Endangered or Vulnerable. Human impacts include both purposeful and accidental take, and loss of nesting beach and foraging habitats. Collection of eggs and breeding adults historically has been the most important factor in their demise, but each year hundreds of thousands also die accidentally in numerous fisheries. Well intentioned, but misguided, management efforts, such as poorly run hatcheries, can undermine their survival further. Marine pollution is also important, as are climate change and global warming. Because all sea turtle populations have distributions comprising multiple range states, priorities for action need to be set regionally as well as nationally. The present status of a population can only be properly evaluated when considered in light of past exploitation, and nesting populations (outwardly) respond only slowly to both over-harvest and protection. Critical habitats need to be identified and protected, and both rookeries and habitats should be monitored. Sources of mortality need to be identified, quantified and mitigated. Community involvement is critical to long-term support for conservation programmes, and there is a growing interest among governments and resource managers to collaborate regionally on marine turtle conservation and management. While numerous agreements to conserve sea turtles and their habitats are being created, their widespread implementation is needed.
