A Morphometric Assessment of the Condition of White Croakers (Genyonemus Lineatus) and Queenfish (Seriphus Politus) with Access to a Wastewater Outfall and a DDT/Polychlorinated Biphenyl Superfund Site: A Los Angeles Outer Harbor Case Study.

Abstract

Sediments and water columns in the Los Angeles Outer Harbor (CA, USA), a major port behind a breakwater, contain DDTs and polychlorinated biphenyls (PCBs) from a nearby Superfund site, and contaminants brought in by ships, boats, stormwater, a river, and a wastewater outfall. White croaker and queenfish, a bottom feeder and a water column feeder, respectively, are two bioindicators for this marine ecosystem. Their condition as populations of fish is assumed to be robust for this role at all times. The present study tests this benign assumption amid progressively increasing DDT/PCB levels in their tissues. The results, as shown by progressively shrinking gonads, show a less than robust white croaker population particularly. Although the males are generally larger than the females, the length (standard [SL] or total [TL]) and body mass (BM) of 80 white croakers collected over 8 years were found to be similar irrespective of gender (177 mm, 212 mm, and 114 g, respectively). Queenfish (67) did not show such similarity over the same period (female: 152 mm SL, 177 mm TL, 56 g BM; male: 145 mm SL, 172 mm TL, 50 g BM). The site-specific expressions/values capturing the current conditions of these fish populations are SL = 0.835[TL] - 1.68 (r2 = 0.914, n = 68) and SL = 0.891[TL] - 8.88 (r2 = 0.961, n = 50) for white croaker and queenfish, respectively. In the allometric growth equation BM = a[SL]b , a and b are 2.83 and 2.49 × 10-4 (r2 = 0.817) for white croakers, and 6.10 and 2.73 × 10-5 (r2 = 0.825) for queenfish, respectively. The relative coefficients of condition Kn are 0.97 ± 0.07 and 1.01 ± 0.12 for white croakers and queenfish, respectively. Molecular-level studies are needed to establish definitively the links between DDT/PCB bioaccumulation in fish tissues and the robustness of the fish populations.Environ Toxicol Chem 2022;41:410-425. © 2021 SETAC.