UC Davis Study Says Lionfish Could Become Established in California Waters

Better recordkeeping of non-indigenous species coming into California urged.

A new study conducted by the University of California, Davis says that marine aquarium species, including the lionfish (subfamily Pteroina, family Scorpaenidae) could become a potential threat to California if they are released into local waterways and become established. While the study says that there have not been any reports of lionfish in California waters, it does say that the Indo-Pacific native fish, which is already established in the Caribbean, the Gulf of Mexico, Florida and neighboring states, could establish itself in the San Francisco Bay and nearby waters as ocean temperatures continue to warm.

Red lionfish near Gilli Banta Island

In the report, “Aquatic Invasive Species Vector Risk Assessments: A Vector Analysis of the Aquarium and Aquascape (‘Ornamental Species’) Trades in California,” lead author Susan Williams, an evolution and ecology professor with the UC Davis Bodega Marine Laboratory says that more than 11 million non-native marine animals destined for the U.S. aquarium trade pass through California’s ports of San Francisco and Los Angeles every year. Of the 102 species that come into California each year, 13 have been found in California waters, 9 of which have become established.

The report also identifies 34 species that can tolerate the state’s marine climate and could become established in California’s coastal waters. Williams told FishChannel that the published scientific evidence on lionfish that have established themselves throughout the Caribbean, Gulf of Mexico, and the east coast of the United States shows that non-native lionfish can survive in waters as low at 53.6 degrees Fahrenheit/12 degrees Centigrade.

Here is a list of marine fishes cited in the study that were for sale in fish stores in the San Francisco Bay area that could potentially survive in the bay and other bodies of water near the bay.

Sergeant major (Abudefduf saxatilis), Scrawled cowfish (Acanthostracion quadricornis), Orange filefish (Aluterus schoepfii), Pygmy angelfish (Centropyge argi), Blueface angelfish (Chaetodontoplus personifer), White angelfish (Chaetodipterus faber), Green chromis damsel (Chromis viridis), Harlequin tuskfish (Choerodon fasciatus), Flying gurnard (Dactylopterus volitans), Porcupine pufferfish (Diodon holocanthus), Red grouper (Epinephilus morio), Banded cat shark (Halaelurus lineatus), Sargassumfish (Histrio histrio), Western jumping blenny (Lepidoblennius marmoratus), Clown goby (Microgobius gulosus), Bigeye squirrelfish (Myripristis jacobus), Red scorpionfish (Rhinopias argolipa), Yasha Hase goby (Stonogobiops yasha).

A list of Caulerpa algae that are sold in fish stores in California, all of which have the potential to become established in California waters. One species, C. taxifolia became established in Agua Hedionda Lagoon, in Carlsbad, Calif. in the early 2000s and was eradicated. These include C. brachypus, C. cupressoides, C. racemosa, C. racemosa var. lamourouxii, C. racemosa var. macrophysa, C. racemosa var. peltata, C. serrulata, C. sertularioides C. taxifolia (established and eradicated),C. peltata, C. prolifera, and C. webbiana.

The researchers also analyzed government databases of non-native species that are common in the ornamental fish trade as well as U.S. Fish and Wildlife Service inspection records for live animals that come into the state via California’s ports and noted that no government agency tracks the final destination of these species once cleared by customs, making it unknown how many species stay in the state. The study includes a large list of recommendations that would help the government better determine what marine species are coming into the United States as well as get a better determination with regard to the numbers of animals coming in as well as improve record keeping by creating a centralized database with centralized authority that all government agencies involved can tap into.

The study authors recommend that the state of California, with participation of the ornamental fish trade, consider short, intermediate, and long term recommendations to develop a system that ensures competent tracking of all non-indigenous ornamental marine species that enter the state. They are listed below as listed in the study.

Management Recommendations-Short term (< 2 years)

  • Implement a single digital permit for non-indigenous species in California
  • Cross-link all agency websites on non-indigenous species
  • Implement a ‘Don’t release’ campaign and assess outcomes
  • Enforce labeling requirements for importations
  • Enhance visibility and accessibility of web information on importation of live species to California starting with a permit pathway diagram (e.g., Fig. 14), including internet links to Best Management Practices currently available
  • Cross-train USFWS inspection agents on Caulerpa taxifolia (USDA) and on Caulerpa species prohibited by California (CDFG)
  • List lionfish as a Restricted Species by its Latin name(s) (Pterois volitans, Pterois volitans/miles, Pterois miles) and by all common names used on internet purchase sites and importation invoices (including common, red, voltans, volitans, red volitans, black peacock, Indian)
  • Initiate discussion with stakeholders improving record keeping and data to determine the relative risk of the vector
  • Enhance regulation of internet sales through the use of web crawlers Intermediate term (2 – 5 years)
  • Require reporting volume of importations in standard units, preferably as individuals
  • Require information on trans-shipping of importations on state and federal permits
  • Require reporting of Restricted Species in possession
  • Digitize and centralize a database on species regulated within both California (including local to state level) and the U.S.
  • Centralize authority for regulation of invasive species in California
  • Provide sufficient resources to support agency mandates (e.g., a surcharge for importations of live organisms or purchases of non-indigenous species)
  • Develop and adopt industry-wide best management practices for commercial, educational, and research aquaria Long-term (> 5 years)
  • Conduct a cross-vector risk assessment
  • Provide more support for, and higher numbers of, USFWS inspection and enforcement agents in California and nationally
  • Collaborate with the ornamental industry to certify aquarium stores for sustainable collecting and best management practices
  • Rectify California non-indigenous species listings with federal listings to streamline agency workloads and foster highly successful cooperation across agencies (e.g., in New York)
  • Conduct a standardized sampling of species and volumes circulating within the main
vectors (‘vector blitz’)
  • Conduct a cross-vector risk assessment based on expert knowledge
  • Quantify trans-shipping flux
  • Conduct an assessment of internet availability of ornamental marine species
  • Investigate the feasibility of ‘white lists’ and ‘black lists’ for ornamental marine species
  • Analyze marine aquarist behaviors in California to estimate the probabilities of release and other determinants of the probability of introduction and possible incentives to reduce the risk
  • Conduct regular surveys of non-indigenous marine species in California, with better coverage of critical habitats (seagrass, kelp)
  • Reassess the numbers and kinds of introduced and established ornamental marine species in California
  • Investigate the diversity (richness, numbers of individuals) of species imported or trans-shipped as live rock
  • Conduct community-level ecological impact experiments
  • Conduct economic impact assessments of the aquarium trade
  • Investigate ceremonial animal releases in California
  • Improve knowledge about non-indigenous marine plants


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