California Department of Fish & Game: Longfin smelt recommended to be classified as “threatened”, additional protections needed

On Tuesday, the California Department of Fish & Game issued it’s findings on the Delta longfin smelt. The Associated Press is reporting that they are recommending additional protections in this all-too-brief article from the San Jose Mercury News.  So, since the AP isn’t going to give more information, I have found the document online, and I’ve copied and pasted the findings and recommendations sections from the Executive Briefing here.

Here are the findings from the report issued by the California Department of Fish and Game. Emphasis added is mine, not theirs. Comments in italics and brackets are also mine:

The longfin smelt is a small fish native to California’s San Francisco Estuary and some other estuaries along the Northeast Pacific coast. Longfin smelt occur in the ocean, bays, estuaries, and rivers. This species feeds exclusively on zooplankton, spawns in freshwater, and has a predominantly 2-year life cycle.

Very little information on longfin smelt abundance in California is available, except for the San Francisco Estuary population. However, the San Francisco Estuary population clearly contains the most individuals in California. Survey data indicates that the population of longfin smelt in the San Francisco Estuary has declined substantially since the 1980s and that other populations in California may have declined similarly. As demonstrated by the following pertinent milestones, the status of longfin smelt has been a concern for decades:

1. Longfin smelt range-wide was proposed for listing under the Federal Endangered Species Act in 1992.
2. The Department classified longfin smelt as a Species of Special Concern by 1995.
3. Moyle et al. (1995) rated longfin smelt as “endangered”, citing these threats in priority order: Reduction in outflows, entrainment1, climatic variation, toxic substances, predation, and introduced species.
4. The American Fisheries Society classified longfin smelt in California as “threatened”. They cited habitat destruction and alteration of spawning and nursery areas, dams, logging, and agricultural water diversions (Musick 2000).

The Department finds that the longfin smelt throughout California should be listed as a Threatened species based on Section 670.1(i) of Title 14 of the California Code of Regulations and Section 2074.6 of the Fish and Game Code.

The Department’s finding is based in large part on the following aspects of the longfin smelt population in the San Francisco Estuary:

1. Longfin smelt abundance has declined substantially and in relation to beneficial freshwater outflow.
2. Low numbers of spawning longfin smelt may result in reproductive failure and increase the likelihood that a catastrophic event could severely affect the population.
3. Longfin smelt are entrained by and lost at water diversions — including diversions for cooling of power plants and diversions operated by the State Water Project, Central Valley Project, municipal entities, and for agricultural and recreational purposes. Continuing entrainment and loss is a threat to longfin smelt recovery.
4. Operations of the State Water Project and the Central Valley Project alter the character and position of the upper estuary salinity gradient. When these operations increase Suisun Bay salinity during the longfin smelt spawning migration, longfin smelt distribution shifts upstream where they are subject to entrainment and loss by diversions. Continuing increased Suisun Bay salinity coupled with increased entrainment and loss at diversions is a threat to longfin smelt recovery.
5. Longfin smelt habitat — including prevalence of exotic species and food items — has changed and the change may be a threat to longfin smelt recovery.
6. A small fraction (14 of 822) of water samples in Suisun Bay, Suisun Marsh and the Sacramento-San Joaquin Delta were acutely toxic to standard aquatic test organisms in laboratory trials. Longfin smelt were present in the vicinity of those locations and may have been adversely affected by toxicity of the water. Continuing water pollution may be a threat to longfin smelt recovery.
7. Managed and other fishes prey on longfin smelt. Piscivorous striped bass, halibut, salmonids, and managed warm-water fishes (e.g., largemouth bass) co-occur — to varying degrees in space and time — with longfin smelt. Piscivorous striped bass number in the millions and are known to eat longfin smelt, salmonids, striped bass, and many other pelagic fishes. Largemouth bass are abundant, their numbers have increased since the 1980s, and they are known to eat many fishes. Little is known about the current populations of other warm-water fishes, but as a group they are considered abundant. Continuing predation on longfin smelt by managed fishes is a threat to longfin smelt recovery.  [Striped bass have been implicated by others (such as the Coalition for a Sustainable Delta) as contributing to the decline of the Delta smelt.  The striped bass is non-native to the Delta.]
8. Little is known about the impacts to longfin smelt attributable to dredging and sand mining in the San Francisco Estuary, but operations conducted in freshwater could entrain adults, eggs, and larvae during winter spawning and incubation while operations in saltwater could entrain juveniles and adults in summer and fall. Loss of longfin smelt to dredging and sand mining operations may be a threat to longfin smelt recovery.
9. A commercial bait fishery for bay shrimp in the San Francisco Estuary takes longfin smelt as by-catch. Historical assessments of juvenile striped bass mortality in the fishery and longfin smelt catches by the fishery suggest that the fishery is a threat to longfin smelt recovery.
10. Longfin smelt are collected from the San Francisco Estuary during research and monitoring to assess threats to their conservation by adverse impacts attributable to development projects. Loss of longfin smelt to scientific collections is a threat to longfin smelt recovery.

Recommendations

Petition Action
1. The Commission should find that classification of longfin smelt as Threatened is warranted.
2. The Commission should publish notice of its intent to amend Title 14 CCR 670.5 to list longfin smelt as Threatened.

Management/Recovery Measures

The Department’s objective is the protection of a sufficient number of longfin smelt to make its long-term survival and recovery in its native habitat and range a certainty.

Because there is not yet a quantitative basis for estimating the benefits of any given action(s), attempting to assure longfin smelt persistence and recovery during the foreseeable future will involve implementing management measures and evaluating their success empirically.

The Department believes the following actions — which are not listed in priority order and are not all under the Department’s authority — would have population-level benefits for longfin smelt:

• Reduce pollution of estuaries by chemicals harmful to longfin smelt and their food web.
• Reduce entrainment and loss of longfin smelt at water diversions — including diversions for cooling of power plants and diversions operated by the State Water Project, Central Valley Project, municipal entities, and for agricultural and recreational purposes. For example, moving State Water Project and the Central Valley Project diversions from the south Sacramento-San Joaquin Delta to the north Sacramento-San Joaquin Delta would reduce loss of longfin smelt to entrainment and loss. [This is an interesting clause.  Without editorializing, I will remind you that the peripheral canal is intended to divert water from the northern Delta, and route it around the Delta to the pumps at the south.]
• Reduce entrainment and loss of adult, juvenile, and larval longfin smelt to dredging.
• Reduce predation on longfin smelt by managed non-native fishes.
• Improve and/or expand habitat for longfin smelt. For example, this could include increasing average December-May Sacramento-San Joaquin Delta outflow, restoring intertidal or shallow subtidal habitat, and/or improving habitat in the flood plain or in open water. [More outflow from the Delta means less diversions from it, although Judge Wanger hasn't necessarily ordered further restrictions when he has considered other restrictions currently in place.  However, in today's game, who knows what will happen.  I'll be looking for further analysis by experts on this.]
• Modify commercial fishery regulations to reduce loss associated with by-catch of longfin smelt.
• Adaptively manage the scientific collection of longfin smelt.

Download the entire report from California of Fish & Game by clicking here.

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