2007 Annual Monitoring Report (pdf 16MB) - Bolsa Chica Lowlands ...

Bolsa Chica Lowlands Restoration Monitoring2007 Annual ReportDue to the difficulty of conclusively distinguishing between juvenile arrow goby (Clevelandia ios) andshadow goby (Quietula y-cauda), juvenile gobies that may have belonged to either species wereidentified as "arrow/shadow goby complex". These functionally similar species commonly co-occurand occupy similar niches in the demersal fish community. Adult arrow and shadow gobies and othergobies were identified to the species level. This method is regularly employed in similar fish studies.All macroinvertebrates captured in the fish sampling nets were collected, identified to the lowesttaxonomic level possible, counted, and released. Due to the tremendous spatial variability of thesespecies in the lagoon and the non-targeted methodology employed here to sample them, collected datawere intended to generate a list of species that occur in the project area, rather than to providedefinitive density and biomass data on their populations.At each study location, physical water quality parameters were measured coincident with the biologicalsampling described above. A Hydrolab Quanta ® multi-probe, calibrated in accordance withmanufacturer specifications, was used to collect temperature, dissolved oxygen, turbidity, and salinitydata. Readings were taken at the bottom and top of the water column.Voucher specimens of any species that were not readily identifiable in the field were collected andpreserved in a 10% buffered formalin/seawater solution and later transferred to 70% ethanol forsubsequent taxonomic analysis in the laboratory. In the lab, the investigator, date of analysis, sampleparameters, and specimen identification were recorded on hard copy data sheets and the specimenstored for future reference.ResultsThe fish and invertebrates captured in the fishing gear are detailed below.FishA total of 18 species of fish, representing 14 families, were captured throughout the study site inOctober 2007 (Table 1-2). The majority of the fish were captured at Station 1, characterizing the fishcommunity at the inner end of the FTB furthest from the ocean. At Station 1, a total of 2,185 fish,represented by 13 species, were captured. The mean density across gear types at Station 1 was 0.52individuals/m 2 . The most abundant species was topsmelt (Atherinops affinis), followed by juvenileanchovy (Anchoa sp.). Together, these two species comprised 95% of the fish captured. The juvenileanchovy were not developed enough to definitively identify them as either deepbody anchovy (Anchoacompressa) or slough anchovy (Anchoa delicatissima). One adult slough anchovy, however, wascaptured in the same haul. California killifish (Fundulus parvipinis) and small kelp bass were capturedalong with a number of juvenile Atherinids. Three California grunion (Leuresthes tenuis) were caughtwith the topsmelt, suggesting the juvenile Atherinids were probably either topsmelt or grunion. Thesespecies often occur together during larval and juvenile stages (Ehrlich et al, 1978) and were notdeveloped enough to definitively identify. Thirty-two juvenile striped mullet (Mugil cephalus) werealso captured at Station 1.Other species that were represented in small numbers at Station 1 were: 2 California needlefish(Strongylura exilis), 2 bay pipefish (Syngnathus leptorhynchus), 2 diamond turbot (Hypsopsettaguttulata), and single individual snubnose pipefish (Syngnathus arctus), bay blenny (Hypsoblenniusgentilis), cheekspot goby (Ilypnus gilberti), and California halibut (Paralichthys californicus).Merkel & Associates, Inc. 28