chapter 6 TRAWL COMMUNITIES AND ORGANISM HEALTH Chapter 6 TRAWL COMMUNITIES AND ORGANISM HEALTH INTRODUCTION (Genyonemus lineatus), California scorpionfish (Scorpaena guttata), ridgeback The Orange County Sanitation District rockshrimp (Sicyonia ingentis), sea (District) Ocean Monitoring Program (OMP) cucumbers (Parastichopus spp.), and crabs samples the demersal (bottom-dwelling) (Cancridae species) are commercially fish and epibenthic macroinvertebrate (EMI andd/or recreationally important. = large invertebrates) organisms to assess effects of the wastewater discharge on The wastewatter outfall has two primary these epibenthic communities and the impacts to the biota of the receiving waters: health of the individual fish within the reef and discharge effects (OCSD 2001, monitoring area (Figure 6-1). The District’s 2004). Reef effects are changes related to National Pollutant Discharge Elimination the physical presence of the outfall System (NPDES) permit requires struucture and associated rock ballast, which evaluation of these organisms to provide a three dimensional hard substrate demonstrate that the biological community habitat that harbors a different suite of within the influence of the discharge is not species than that found on the surrounding degraded and that the outfall is not an softt bottom. As a result, stations located epicenter of diseased fish (see box). near the outfall pipe can have greater Species, such as California halibut species diversity and an increased number (Paralichthys californicus), white croaker of predators. Compliance criteria pertaining to trawl communities and organism health contained in the District’s NPDES Ocean Discharge Permit (Order No. R8-2004-0062, Permit No. CAO110604). Criteria Description C.5.a Marine Communities Marine communities, inncluding vertebrates, invertebrates, and algae shall not be degraded. C.5.b Marine Resources The natural taste, odor, and color of fish, shellfish, or other marine resources used for human consumption shall not be altered. C.5.c Human Health Concerns The concentration of organic materials in fish, shellfish, or other marine resources used for human consumption shall not bioaccumulate to levels that are harmful to human health. 6.1 20m 10m 33° 40’ N )SS Eva Emmy 0 2 4 kilometers Edison Outfall 40m OCSD 78” Outfall T0 6 . T11 2 S T6 Edith T2 T13 33° 35’ N Elly S OCSD 120” S Outfall T3 60m Ellen T12 T14 T1 80m 100m S Eureka T10 200m 300m W W W ’ ’ ’ 5 0 5 . 0 0 5 ° ° ° LA-3 8 8 7 1 1 1 400m 1 1 1 Dumpsite Figure 6-1. Otter trawl stations for semi-annual surveys, 2009-10. Orange County Sanitation District, California. Discharge effects are changes related to human health concern; 2) are there the release of treated effluent. temporal and/or spatial patterns relative to Contaminants adhere to organic the ocean outfall; and 3) are the marine particulates in the effluent, which then sink organisms in the monitoring area generally to the ocean bottom where they become a healthy? food resource for many invertebrate species. These, in turn, may be consumed by fish. The contaminants that accumulate METHODS in the invertebrates may then be transferred up the food chain to fish and other, higher Field Methods order predators. Many demersal fish (e.g., flatfish) feed directly or indirectly on Demersal fish and epibenthic invertebrate prey that live in or on the macroinvertebrates (EMI) species were bottom sediments. Furthermore, they live collected in July 2009 and January 2010 in direct contact or in close association with using a 7.6 meter wide, Marinovich, semi- these sediments and consequently have an balloon otter trawl net fitted with a 0.64 cm increased probability of direct exposure to cod-end mesh net. The net was towed on sediments containing discharged particles. the ocean bottom for 450 m at approximately The transfer of chemical contaminants 2 knots along a pre-determined course. through consumption of benthic infauna can Sampling was conducted at 9 permit make demersal fish species particularly stations: inner shelf (36 m) Stations T2 and susceptible to physical abnormalities and T6; middle shelf (60 m) Stations T1, T3, T11, diseases (Johnson et al. 1992, 1993; Moore T12, and T13; and outer shelf (137 m) et al. 1997; Myers et al. 1993; Stehr et al. Stations T10 and T14 (Figure 6-1). Two 1997, 1998). replicate hauls were conducted at the inner and outer shelf stations and 3 replicate hauls Contaminants, especially lipid-soluble were conducted at the middle shelf stations (lipophilic) compounds, such as chlorinated during both surveys. Additionally, 1 haul pesticides (e.g., DDT) and polychlorinated was collected at T0 (18 m) in July 2009 to biphenyls (PCBs) can accumulate in maintain a historical database, but the data organisms at concentrations several orders are not presented in this report. of magnitude higher than in surrounding sediments or water through the process of Trawl caught specimens were identified to bioaccumulation. Further, certain organic the lowest possible taxon, typically to compounds can increase in concentration species. A minimum of 30 individuals of in organisms at higher levels of the food each fish species were measured chain via biomagnification, including individually to the nearest millimeter humans and marine mammals. Whether (standard length) and weighed to the bioaccumulated or biomagnified, high tissue nearest gram. Fish in excess of 30 contaminant concentrations may result in individuals were enumerated in 1 cm size greater susceptibility to disease or classes and batch weighed. All fish reproductive impairment (Arkoosh et al. specimens were examined for external 1998). tumors, other lesions, and parasites since gross external manifestations may indicate To assess this issue, the District uses contaminated sediments (Murchelano 1982). tissue contaminant data to evaluate the The first 100 EMI were also enumerated by following aspects of permit compliance: 1) species and weighed to the nearest gram. are contaminant concentrations in fish Specimens with abundance greater than muscle tissue sufficient to pose a potential 100 individuals were weighed in batches and 6.3 abundance calculated based on the multidimensional scaling (MDS). Data were weight/abundance ratio. Fish and EMI averaged by station and truncated to include specimens that could not be identified in the only the middle shelf (60 m) stations since field were retained for further identification depth is a strong environmental factor in (FID) and weighed and measured in the delineating species clusters (OCSD 2004, laboratory. Fish from 4 target species were 2010). Clarke and Warwick (2001) warn that also collected for bioaccumulation studies: clustering is less useful and may be hornyhead turbot (Pleuronichthys verticalis), misleading where there is a strong bigmouth sole (Hippoglossina stomata), environmental forcing, such as depth. Prior English sole (Parophrys vetulus), and Pacific to the calculation of the Bray-Curtis indices, sanddab (Citharichthys sordidus). Pacific the data were square-root transformed in sanddabs were collected as composite order to down-weight the highly abundant samples. The sampling objective was to species and incorporate the importance of collect 10 individuals of at least 3 of the 4 the less common species (Clarke and target species at both outfall (T1/T12) and Warwick 2001). The SIMPER (“similarity farfield (T11/T13) sites. More detailed field percentages”) routine was also used to and laboratory methods are provided in determine inter- and intra-group species Appendix A. differences. Data Analyses Community measures from Stations T1 and T11 were evaluated for long-term temporal Fish and EMI populations were summarized and spatial patterns, and compared with in terms of total abundance and species, regional reference conditions, such as 1994 percent abundance, frequency of Southern California Bight Pilot Project occurrence, and mean abundance per haul. (SCBPP), Bight’98, Bight’03, and Bight’08 In addition, mean number of species, regional monitoring programs (Allen et al. number of individuals, biomass, and 1998, 2002, 2007, respectively). diversity indices including Shannon-Wiener (H’), Margalef’s Species Richness (SR), Fish biointegrity in the District’s monitoring and Swartz’s 75% Dominance (75DOM) area was assessed using the fish response were calculated for both fish and EMI. In index (FRI). The FRI is a multivariate some analyses, stations were grouped into weighted-average index produced from an the following categories to assess spatial or ordination analysis of calibrated species depth-related patterns: “outfall” (Stations T1 abundance data (see Allen et al. 2001, and T12); “shallow” (Stations T2 and T6); 2006). The FRI was calculated for all 9 “deep” (Stations T10 and T14); “farfield stations in 2009-10. For a historical downcoast” (Station T3); and “farfield perspective, FRI was calculated from 1985 upcoast” (Stations T11 and T13). to 2009 for outfall Station T1 and upcoast reference Station T11. PRIMER v6 (Plymouth Routines in Multivariate Ecological Research) In order to evaluate human health risk, the multivariate statistical software was used to non-lipid normalized muscle tissue examine the spatial patterns of the fish concentrations of hornyhead turbot and assemblages in the District’s monitoring English sole were compared to state and area (Clarke 1993, Warwick 1993). federal human consumption guidelines. Analyses included hierarchical clustering Nearfield and farfield station muscle and with group-average