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

COMPTUEX/JTFEX EA/OEA Final Chapter 3Midwater FishMidwater or mesopelagic fish are pelagic and inhabit depths of 164–1,969 ft (50–600 m). Manymidwater fish are strong swimmers; migrate to surface waters each night and return to deep water duringthe day; have well developed eyes, swim bladders, and photophores (light-producing organs); and areshaded dark on the dorsal (upper) surface and light on the ventral (lower) surface. In contrast,bathypelagic fish, which inhabit the deepest waters, are generally weak swimmers; have either no orpoorly developed eyes, swim bladders, and photophores; and are black or brown in color (Brown, 1974).There are about 120 species of midwater fishes in the SCB. Only a small percentage of these areimportant commercially. Northern species are associated with the lower mesopelagic zone, where Pacificsubarctic water is the dominant water mass and are most common in winter and spring when intrusions ofthis northern water mass are greatest. Southern species are most common during summer and fall whenwater of southern origin intrudes. Central Pacific species are represented by only a few species (Cross andAllen, 1993).Table 3.3-4. Species Characteristic of Sandy Beach Open Coast, Nearshore, and Offshore SoftSubstrates in the SCBSpecies Open Coast Nearshore Offshore Species Open Coast Nearshore OffshoreGray smoothhoundsharkA A White croaker A A AShovelnose guitarfish A A Spotfin croaker ASpiny dogfish B Queenfish A, B A, B ARound stingray A A California corbina ANorthern anchovy A, B A, B A Yellowfin croker ADeepbody anchovy A A Barred surfperch ASlough anchovy A A Shiner surfperch A, B A, B A, BCalifornia lizardfish A A Pile surfperch A, B A, B APacific hake A A Black surfperch A A ASpotted cusk-eel A A Walleye surfperch A, B A, B ABasketweave cusk-eel A A Dwarf surfperch A ABlackbelly eelpout A White surfperch A, B A, B ASpecklefinmidshipmanA A Pink surfperch A A, BPlainfin midshipman A A California barracuda A, B A, BCalifornia killifish A Giant kelpfish A ATopsmelt A, B A, B A Arrow goby AJacksmelt A, B A, B Blackeye goby A ACalifornia grunion A Bay goby A AKelp pipefish A A Pacific butterfish BCalifornia scorpionfish A A Pacific sanddab A A, BCalico rockfish A A, B Speckled sanddab A A3-21 February 2007