Composite Training Unit Exercises and Joint Task ... - Govsupport.us

COMPTUEX/JTFEX EA/OEA Final Chapter 4fish (Anon., 1970). Sudden changes in noise level can cause fish to dive or to avoid the sound bychanging direction. Time of year, whether the fish have eaten, and the nature of the sound signal may allinfluence how fish will respond to the sound.In the studies that have been conducted, effects of noise or sonar have been noted at the individual level.However, these studies have focused on a few species and it is not known whether their responses arerepresentative of the wide diversity of other marine fish species. Based on the limited informationcurrently available, mid-frequency active sonar is not likely to injure or kill fish, and any behavioralavoidance of an area is expected to be temporary. Fish species are unlikely to be affected at thepopulation level. Note that the SOCAL OPAREA has maintained a healthy and thriving population ofmany recreationally and commercially important fish species in concert with the historical use of the areafor Navy training.4.3.1.4 Effects on Essential Fish HabitatThis section discusses the potential impacts to Essential Fish Habitat (EFH) established for speciesmanagement under Fishery .Management Plans (FMPs). Coastal Pelagics and Pacific Groundfish(NMFS, 1998) may utilize both nearshore and offshore areas during their lives, as eggs and larvae formost species are planktonic and can occur in nearshore and offshore waters, while adults may be presentin nearshore and/or offshore waters. EFH is established for the life stages of managed species.Adverse effects mean any impact that reduces quality and/or quantity of EFH. Adverse effects mayinclude direct or indirect physical, chemical, or biological alterations of the waters or substrate and lossof, or injury to, benthic organisms, prey species and their habitat, and other ecosystem components, ifsuch modifications reduce the quality and/or quantity of EFH. Adverse effects to EFH may result fromactions occurring within EFH or outside of EFH and may include site-specific or habitat-wide impacts,including individual, cumulative, or synergistic consequences of actions (50 CFR 600.810(a)).Rocky substrate can support extensive communities and provides habitat for a diverse ecosystem of fish,invertebrates, and algae. Live bottoms, as defined by the Bureau of Land Management, are areas“containing biological assemblages consisting of such sessile invertebrates as sea fans, sea whips,hydroids, anemones, ascidians, sponges, bryozoans, and hard corals living upon and attached to naturallyoccurring hard or rocky formations with rough, broken, or smooth topography; and whose lithotopefavors accumulation of turtles, pelagic and demersal fish.” In the SOCAL OPAREA, colonized hardbottom, macroalgae, invertebrates, and deep-slope terraces are found near San Clemente Island , and theoffshore banks (e.g., Tanner and Cortes).. The marine benthic invertebrate assemblages are extremelydiverse and include representatives of nearly all phyla.The majority of the operations that use live munitions, bombs, or missiles occur in the open ocean awayfrom sensitive nearshore benthic habitats. Underwater detonations will occur in areas of soft bottom.Rocky substrate, colonized hard bottoms, and live bottom habitat will be avoided. The conduct of allvessel sinkings in water at least 1,000 fathoms (6,000 feet) deep and at least 50 nautical miles from land.Therefore, SINKEX operations would not destroy or adversely effect sensitive benthic habitats.Expendable materials such as sonobuoys, torpedoes, targets, munitions, intact missiles would eventuallysink to the bottom, and are unlikely to result in any physical impacts to the sea floor because they wouldsink into a soft bottom, where they eventually would be covered by shifting sediments. Soft-bottomhabitats are less sensitive than hard bottom habitats, and, in such areas, the effects of expended materialswould be minimal. Rates of deterioration would vary, depending on material and conditions in theimmediate marine and benthic environment.4-15 February 2007