Delta smelt

Source: Wikipedia, the free encyclopedia.

Delta smelt

Critically Endangered  (IUCN 3.1)[1]

ESA)[2][3]
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Osmeriformes
Family: Osmeridae
Genus: Hypomesus
Species:
H. transpacificus
Binomial name
Hypomesus transpacificus

The delta smelt (Hypomesus transpacificus) is an endangered

indicator species for the overall health of the Delta's ecosystem.[5]

Because of its one-year lifecycle and relatively low

functionally extinct in the wild.[8]

Taxonomy and evolution

H. olidus

H. nipponensis

H. japonicus

H. pretiosus

H. transpacificus

Phylogeny of the genus Hypomesus.[9]

The delta smelt is one of five currently recognized

Pacific, and also "to the friendship of Japanese and Canadian ichthyologists." He separated these geographically isolated populations into separate subspecies: H. t. transpacificus and H. t. nipponensis.[10]

Modern analysis of the genus would elevate all of McAllister's subspecies to full species status, based on fin ray counts and the number of chromatophores between their mandibles, a change which genetic analysis has supported.

clades.[12]

The abbreviated distribution of Hypomesus species along both the east and west sides of the Pacific Ocean suggests that their common ancestor had a range that would have crossed the Pacific. Researchers have hypothesized that climatic changes may have reduced the range of the ancestral species during cooling periods, which would have created a reproductive barrier, allowing

epoch.[9]

Habitat

The delta smelt is endemic to the Sacramento–San Joaquin River Delta in California, where it is distributed from the

pelagic (lives in the open water column away from the bottom) and euryhaline
species (tolerant of a wide salinity range). It has been collected from estuarine waters with salinities up to 14 parts per thousand.

Historically, delta smelt were distributed from San Pablo Bay upstream to Sacramento on the Sacramento River and Mossdale on the San Joaquin River, which varied seasonally and with freshwater outflow.[13] Today, large areas of historic delta smelt habitat and designated critical habitat have become unsuitable for some life history stages of the species, though key environmental characteristics (e.g. temperature, salinity, water depth) of these areas have not changed.[14][15] Delta smelt disappeared from the southern portion of their historic habitat in the late 1970s, which coincides with substantial increases in the amounts of water exported from the delta. Water export operations likely have a great effect on the distribution, abundance, and genetic diversity of delta smelt.[16]

Lifecycle

The delta smelt is

semelparous
, living one year and dying after its first spawning. Their spawning occurs in spring in river channels and tidally influenced backwater sloughs upstream of the mixing zone where salt water meets fresh water. The Sacramento and San Joaquin Rivers then transport the delta smelt larvae downstream to the mixing zone, normally located in the Suisun Bay. Young delta smelt then feed and grow in the mixing zone before starting their upstream spawning migration in late fall or early winter.

The delta smelt is preyed upon by larger fish, especially striped bass and largemouth bass, which are introduced species in the Sacramento-San Joaquin Delta.[17]

Endangered status

Historically, delta smelt were relatively abundant in the upper Sacramento-San Joaquin Estuary, with populations declining dramatically in the 1980s.[18] They were listed as threatened by both federal and state governments in 1993, and sustained record-low abundance indices, prompted their listing as endangered under the California Endangered Species Act in 2010.[19][20] Critical habitat was listed for delta smelt on December 19, 1994.[21]

Delta smelt are threatened with extinction due to anthropogenic alterations to their ecosystem, including urbanization, non-native species, water diversions, contaminants, and the conversion of complex tidal habitats to leveed channels.

U.S. Fish and Wildlife Service near Shasta Dam.[8]

Court protection

In 2005, the U.S. Fish and Wildlife Service (FWS) issued a biological opinion that the

arbitrary and capricious and ordered protections for the delta smelt while the document was redone.[24]

In 2008, at the close of the court's deadline, the FWS issued a new biological opinion.[25] This time, the FWS came to the opposite of its earlier conclusion, finding the water projects were jeopardizing the continued existence of the delta smelt.[26] When six new plaintiffs sued, Judge Wanger preliminarily ordered the FWS to give him weekly justifications of delta flow restrictions and appointed four scientists as his own expert witnesses.[27] After haranguing FWS expert witnesses as “zealots”,[28] in December 2010 Judge Wanger, again, found the FWS BioOp was arbitrary and capricious and, again, ordered the FWS to complete a new one.[29]

In 2014, a divided panel of the

TVA v. Hill's command that endangered species must be saved "whatever the cost", Circuit Judge Jay Bybee opined that California could only use the smelts' water after receiving an exemption from the God Squad.[32] In January 2015 the U.S. Supreme Court declined review without comment.[33]

The smelt is unpopular among farmers, with a common complaint being that 200,000 acres of farmland have been left fallow due to "four buckets of minnows".

UC Davis study estimated that job losses due to smelt protection were closer to 5,000.[36]

See also

References

  1. ^
    doi:10.2305/IUCN.UK.2014-3.RLTS.T10722A174778740.en
    . Retrieved 7 May 2023.
  2. ^ a b "Delta smelt (Hypomesus transpacificus)". Environmental Conservation Online System. U.S. Fish & Wildlife Service. Retrieved 7 May 2023.
  3. ^ a b 58 FR 12854
  4. ^ Sommer, T. et al. 2011. The spawning migration of delta smelt in the Upper San Francisco Estuary. San Francisco Estuary and Watershed Science: 9(2).
  5. ^ "Delta Smelt". Center for Biological Diversity. Retrieved 10 May 2015.
  6. ^ Moyle, PB. 2002. Inland fishes of California. University of California Press, Berkeley.
  7. ^ "Delta Smelt". U.S. Fish & Wildlife Service. 30 December 2015. Archived from the original on 19 March 2016.
  8. ^
    San Jose Mercury News
    . Retrieved 9 May 2015.
  9. ^
    S2CID 4488913
    .
  10. ^ a b McAllister DE (1963). "A revision of the smelt family, Osmeridae". National Museum of Canada Bulletin. 191. Department of National Affairs and National Resources: 29–31.
  11. ^ Sweetnam DA (1995). "Field identification of delta smelt and wakasagi". Interagency Ecological Program for the Sacramento-San Joaquin Estuary Newsletter (Spring): 1–3.
  12. PMID 19015040
    .
  13. ^ Radtke, LD (1966) Distribution of smelt, juvenile sturgeon and starry flounder in the Sacramento-San Joaquin Delta. In: Fish bulletin. California Department of Fish and Game, Sacramento, pp 115–129
  14. ^ CDFG (2003) Comment letter on the five-year status review of the delta smelt. California Department of Fish and Game, California, p 6
  15. ^ Miller J, Swanson C, Poole KS (2006) Emergency petition to list the delta smelt (Hypomesus transpacificus) as an endangered species under the Endangered Species Act. Center for Biological Diversity, Bay Institute, & Natural Resources Defense Council.
  16. ^ Bennett, WA (2005) Critical assessment of the delta smelt population in the San Francisco Estuary, California. San Francisco Estuary Watershed Sci 3:1–71.
  17. ^ Raymond Bark; Brent Bridges; Dr. Mark D. Bowen (2008). "2008 Tracy Research Study: Plan Predator Impacts on Salvage Rates of Juvenile Chinook salmon and Delta Smelt". Archived from the original on June 29, 2010. Retrieved 2009-06-26.
  18. ^ Newman KB (2008) Sample design-based methodology for estimating delta smelt abundance. San Francisco Estuary Watershed Sci 6:1–18.
  19. ^ CDFG (2010) State & federally listed endangered & threatened animals of California. California Department of Fish & Game,State of California, The Natural Resources Agency, California.
  20. ^ Federal Register 58:12863; March 5, 1993
  21. ^ Federal Register 59:65256
  22. ^ Nichols FH, Cloern JE, Luoma SN, Peterson DH (1986) The modification of an estuary. Science 231:567–573.
  23. ^ "Federal Judge Throws Out Biological Opinion for Threatened Delta Smelt". 2007-05-25.
  24. ^ Natural Resources Defense Council v. Kempthorne, 506 F. Supp. 2d 322 (E.D. Cal. 2007).
  25. ^ "OCAP, Operational Criteria and Plan, Bay-Delta Fish & Wildlife Office, USFWS". www.fws.gov. Archived from the original on 2012-11-12.
  26. ^ Jenkins, Matt (10 December 2010). "California's Tangled Water Politics". High Country News. Vol. 42, no. 22. Archived from the original on 22 May 2015. Retrieved 22 May 2015.
  27. ^ "The Consolidated Delta Smelt Cases | California Water Law Journal".
  28. ^ "Judge's comments in Delta smelt case raised eyebrows". 2011-09-28.
  29. ^ San Luis & Delta-Mendota Water Auth. v. Salazar, 760 F. Supp. 2d 855, 863 (E.D. Cal. 2010).
  30. ^ http://www.pacificlegal.org/releases/10-1-14-Stewart-and-Jasper-1-1347 citing San Luis & Delta-Mendota Water Authority v. Jewell, 747 F.3d 581 (9th Cir. 2014).
  31. ^ Id., see oral argument video at [1].
  32. ^ San Luis & Delta-Mendota Water Authority v. Jewell, 747 F.3d 581 (9th Cir. 2014) citing Eric M. Yuknis, Note, Would a “God Squad” Exemption under the Endangered Species Act Solve the California Water Crisis?, 38 B.C. Envtl. Aff. L. Rev. 567 (2011).
  33. ^ "State Water Contractors v. Jewell".
  34. ^ Cooke, Charles C. W. (27 January 2014). "Green Drought, For the sake of the smelt, California farmland lies fallow". The National Review. Retrieved 22 May 2015.
  35. ^ ABC KFSN-TV "Water Shortage in the Central Valley"
  36. ^ Howitt, R., Josue Medellin-Azuara, Duncan MacEwan. "Measuring the Employment Impact of Water Reductions" Department of Agriculture and Resource Economics and Center for Watershed Sciences, UC Davis, September 2009

External links

Retrieved from "https://en.wikipedia.org/w/index.php?title=Delta_smelt&oldid=1198889969"