| Water Body Name: | Bodega HU, Bodega Harbor HA |
| Water Body ID: | CAB1152200020020108171136 |
| Water Body Type: | Bay & Harbor |
DECISION ID |
6780 |
Region 1 |
Bodega HU, Bodega Harbor HA |
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| Pollutant: | Invasive Species |
| Final Listing Decision: | List on 303(d) list (TMDL required list) |
| Last Listing Cycle's Final Listing Decision: | List on 303(d) list (TMDL required list)(2006) |
| Revision Status | Original |
| Sources: | Source Unknown |
| Expected TMDL Completion Date: | 2019 |
| Impairment from Pollutant or Pollution: | Pollutant |
| Regional Board Conclusion: | This pollutant is being considered for placement on the Section 303(d) List under Section 3.10 of the Listing Policy. Under Section 3.10 a single line of evidence is necessary to assess listing status.
Two lines of evidence are available in the administrative record to assess this pollutant. Over a nine-year period, experiments strongly indicated that non-native presence was responsible for sharp native benthic community abundance declines in Bodega Bay Harbor. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the Section 303(d) List in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: (1) This study was conducted from 1989-1998, excluding 1992. (2) Path analysis was applied on and similar methods were used to measure abundance data. (3) The non-native European green crab exerted 'top-down' control significantly reducing the abundances of several native invertebrate species monitored, which showed sharp declines within 3 years of green crab arrival. (4) Field and lab experiments indicated green crab predation was responsible for these declines. (5) It cannot be determined if the trend in water quality is expected to meet water standards by the next listing cycle. (6) Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. |
| Regional Board Decision Recommendation: | This is a decision made by the State Water Resources Control Board and approved by the USEPA in 2006 . No new data were assessed by the Regional Board for 2008. The decision has not changed. |
| State Board Review of Regional Board Conclusion and Recommendation: | |
| State Board Decision Recommendation: | After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board. |
| USEPA Action (if applicable): | USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant. |
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| LOE ID: | 2 | ||||
| Pollutant: | Invasive Species | ||||
| LOE Subgroup: | Population/Community Degradation | ||||
| Matrix: | Not Specified | ||||
| Fraction: | None | ||||
| Beneficial Use: | Marine Habitat | ||||
| Number of Samples: | 0 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | Not Specified | ||||
| Data Used to Assess Water Quality: | The non-native European green crab was first reported in 1989-90 from San Francisco Bay and had spread to Bodega Bay by 1993. A predatory non-native New Zealand sea slug was collected in San Francisco Bay in 1992 and is now found from San Diego to Bodega Harbor (Cohen, A.N. 1997). | ||||
| Data Reference: | Placeholder reference 2006 303(d) | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. Use of indicator organisms, analysis of species diversity, population density, growth anomalies, bioassays of appropriate duration, or other appropriate methods as specified by the Regional Water Board will determine compliance with this objective. | ||||
| Objective/Criterion Reference: | Placeholder reference 2006 303(d) | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | |||||
| Temporal Representation: | |||||
| Environmental Conditions: | Changes in relative diversity and abundance of native species may also be driven by habitat alteration, flow changes, or hydro-modification. | ||||
| QAPP Information: | Peer Reviewed Journal Article | ||||
| QAPP Information Reference(s): | |||||
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| LOE ID: | 3 | ||||
| Pollutant: | Invasive Species | ||||
| LOE Subgroup: | Population/Community Degradation | ||||
| Matrix: | Water | ||||
| Fraction: | None | ||||
| Beneficial Use: | Marine Habitat | ||||
| Number of Samples: | 0 | ||||
| Number of Exceedances: | 0 | ||||
| Data and Information Type: | Not Specified | ||||
| Data Used to Assess Water Quality: | Non-native green crab (Grosholz et al., 2000) was first observed in 1993 in Bodega Bay Harbor, CA. This study measured the impact of the green crab, Carcinus maenus, on a coastal marine food web and found this predator exerted strong 'top-down' control, significantly reducing the abundances of several native invertebrate species monitored over a nine year period (Grosholz et al. 2000). Several native species showed sharp declines within three years of the arrival of green crabs. Field and lab experiments indicated that green crab predation was responsible for these declines. To analyze the strength of direct and indirect impacts of green crab predation, path analysis was employed on the abundance data. | ||||
| Data Reference: | Placeholder reference 2006 303(d) | ||||
| SWAMP Data: | Non-SWAMP | ||||
| Water Quality Objective/Criterion: | All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. Use of indicator organisms, analysis of species diversity, population density, growth anomalies, bioassays of appropriate duration, or other appropriate methods as specified by the Regional Water Board will determine compliance with this objective. | ||||
| Objective/Criterion Reference: | Placeholder reference 2006 303(d) | ||||
| Evaluation Guideline: | |||||
| Guideline Reference: | |||||
| Spatial Representation: | Bodega Bay Harbor (BBH) in California is two kilometers squared in area. Abundance of all crab species was estimated using three pitfall traps at 50-meter intervals along four transect lines parallel to the shoreline. Benthic invertebrate abundance and both native shore crab species were measured along the four transects. In April of each year, a total of six core samples were taken at 20-meter intervals along these transects for both Nutricola species. The same method was used to estimate changes in selected invertebrates at other sites in BBH. | ||||
| Temporal Representation: | The time period, unless otherwise specified is from 1989-1998, excluding 1992. Abundance of all crab species was estimated annually in late May to early June. Actual density of green crabs was estimated visually 2-4 times annually from 1994-1996. Invertebrate abundance was measured annually. Abundance for both native shore crab species was measured during April of each year. The same time period was used to estimate changes in selected invertebrates at other sites in BBH, and for 13 species of wintering shorebirds. For the shorebirds, data were collected three times annually (Aug 15 to Sept 30, Nov 15 to Dec 31, and Jan 15 to Feb 28). | ||||
| Environmental Conditions: | Changes in relative diversity and abundance of native species may also be driven by habitat alteration, flow changes, or hydro-modification. | ||||
| QAPP Information: | Peer Reviewed Journal Article. | ||||
| QAPP Information Reference(s): | |||||