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<br />5 <br /> <br />. enhance reproduction/survival of trout, predators of humpback <br />chub <br />Recovery Factor B.-Protection from Overutilization for Commercial, <br />Recreational, Scientific, or Educational Purposes <br />4. Handling for scientific studies <br />. repeated capture and marking (PIT tagging) may lead to delayed <br />mortality <br />5. Effects of recreational use <br />. Recreational use of the LCR may affect reproductive habitat or <br />interfere with reproduction <br />Recovery Factor C.-Adequate Protection from Disease or Predation <br />6. Asian tapeworm, Lernaea anchor copepod <br />. Asian tapeworm is currently at a high incidence of infestation in <br />the Little Colorado River (LCR) (about 90% oflarge juveniles and <br />adults are infested); require cyclopoid copepod as intermediate <br />host, require 20 C to mature and reproduce; severe infestation can <br />impact gut, lead to death <br />. Lernaea anchor copepod; require 200C to mature and reproduce; <br />usually does not lead to death, although anchor wounds may fester <br />and infect <br />. Note: whirling disease and intestinal nematodes are not found in <br />humpback chub, but could become problematic for trout in the <br />tail water fishery with warmer water temperatures. <br />7. Escape of nonnative fish into the Colorado River and its tributaries in <br />Grand Canyon <br />. Numerous potential predators and competitors of humpback chub <br />occupy various tributaries and can invade Grand Canyon, given <br />suitable conditions <br />8. Predation by nonnative warm water fish species <br />. Channel catfish and black bullhead are known predators of <br />humpback chub <br />. Common carp may consume large numbers of incubating eggs <br />. Red shiners and fathead minnows compete with and prey upon <br />young native fish in nursery habitats <br />9. Predation by nonnative cold water fish species <br />. Brown trout and rainbow trout are known predators of humpback <br />chub <br />Recovery Factor D.-Adequate Existing Regulatory Mechanisms <br />10. Protection of habitat and flow <br />. Long-term legal protection of habitat and flow in the LCR and <br />mainstem is necessary for long-tenn conservation of humpback <br />chub <br />II. Need for Conservation Plans <br />. Recovery Goals call for Conservation Plans to be implemented at <br />the time of delisting to assure continued and long-tenn <br />conservation of humpback chub <br /> <br />T ,...-~; ,,- ry' <br />~'. 1 : <br />~ J <br />