Integrating High-Resolution Coastal Acidification Monitoring Data Across Seven United States Estuaries

Beginning in 2015, the United States Environmental Protection Agency’s (EPA’s) National Estuary Program (NEP) started a collaboration with partners in seven estuaries along the East Coast (Barnegat Bay; Casco Bay), West Coast (Santa Monica Bay; San Francisco Bay; Tillamook Bay), and the Gulf of Mexico (GOM) Coast (Tampa Bay; Mission-Aransas Estuary) of the United States to expand the use of autonomous monitoring of partial pressure of carbon dioxide (pCO2) and pH. Analysis of high-frequency (hourly to sub-hourly) coastal acidification data including pCO2, pH, temperature, salinity, and dissolved oxygen (DO) indicate that the sensors effectively captured key parameter measurements under challenging environmental conditions, allowing for an initial characterization of daily to seasonal trends in carbonate chemistry across a range of estuarine settings. Multi-year monitoring showed that across all water bodies temperature and pCO2 covaried, suggesting that pCO2 variability was governed, in part, by seasonal temperature changes with average pCO2 being lower in cooler, winter months and higher in warmer, summer months. Furthermore, the timing of seasonal shifts towards increasing (or decreasing) pCO2 varied by location and appears to be related to regional climate conditions. Specifically, pCO2 increases began earlier in the year in warmer water, lower latitude water bodies in the GOM (Tampa Bay; Mission-Aransas Estuary) as compared with cooler water, higher latitude water bodies in the northeast (Barnegat Bay; Casco Bay), and upwelling-influenced West Coast water bodies (Tillamook Bay; Santa Monica Bay; San Francisco Bay). Results suggest that both thermal and non-thermal influences are important drivers of pCO2 in Tampa Bay and Mission-Aransas Estuary. Conversely, non-thermal processes, most notably the biogeochemical structure of coastal upwelling, appear to be largely responsible for the observed pCO2 values in West Coast water bodies. The co-occurrence of high salinity, high pCO2, low DO, and low temperature water in Santa Monica Bay and San Francisco Bay characterize the coastal upwelling paradigm that is also evident in Tillamook Bay when upwelling dominates freshwater runoff and local processes. These data demonstrate that high-quality carbonate chemistry observations can be recorded from estuarine environments using autonomous sensors originally designed for open-ocean settings.

Field Trial Comparing Two Materials for Marine Oil Sheen Sampling

The California Department of Fish and Wildlife (CDFW) uses fiberglass material for forensic analysis of oil sheens, while the United States Coast Guard (USCG) method uses a tetrafluoroetheylene-fluorocarbon (TFE-fluorocarbon) polymer net. We performed a field trial of these two materials by sampling natural oil seeps, two in Santa Monica Bay, and three sheen areas in the Santa Barbara Channel. Though the fiberglass material did collect less mass on some trials, the forensic chemistry results demonstrated that both materials were satisfactory for purposes of chemical forensic analysis as each pair of the sampling materials yielded results that were consistent with a common oil seep source.

Planning to adaptation: Informing regional nature-based adaptation to improve coastal resiliency in Santa Monica Bay

Los Angeles County is known for its wide sandy beaches, coastal boardwalks, and beach commerce and tourism. Planning for sea level rise and associated coastal hazards poses unique challenges in highly populated urban communities; in particular, sandy beaches play an important role in buffering the land from sea level rise, coastal storms, and associated flooding. With increasing pressure to prepare for and adapt to sea level rise, boundary organizations such as USC Sea Grant and The Bay Foundation are helping coastal communities build their capacity to respond to changing shorelines by providing and translating best available science, providing planning and technical support, building partnerships, and implementing adaptation strategies. This paper evaluates the process and provides recommendations for translating science to on-the-ground planning and adaptation efforts in coastal communities. Regionally, USC Sea Grant’s AdaptLA initiative works with coastal communities to communicate sea level rise science and provide managers with information and tools to assess vulnerabilities and begin to plan for adaptation. Informed by detailed, scaled-down climate change models and science-based demonstration projects, some AdaptLA participants initiated demonstration adaptation projects such as the Santa Monica Beach Restoration Pilot Project discussed in this paper. The Santa Monica Bay case study highlights a sea level rise adaptation process, from community capacity building to planning nature-based adaptation, using beach restoration. Lessons learned from demonstration projects in the region can inform similar projects and potential scaling up of nature-based adaptation on sandy beaches. Through the collective effort of boundary organizations, coordination with multiple jurisdictions and agencies, and community support, this case study demonstrates a model for implementing naturebased adaptation in urban coastal communities.

Heavy metal accumulation in Lacistorhynchus dollfusi (Trypanorhyncha: Lacistorhynchidae) infecting Citharichthys sordidus (Pleuronectiformes: Bothidae) from Santa Monica Bay, Southern California

SUMMARYThe accumulation of heavy metals in macroparasites of fish has been widely studied in freshwater environments. Less is known about metal uptake in cestodes parasitizing marine fish. Lacistorhynchus dollfusi is a common larval cestode parasite of Pacific sanddab (Citharichthys sordidus), a flatfish species inhabiting Santa Monica Bay. The ability of this cestode to concentrate metals in its tissues was compared with metal levels in its sanddab host. Fish and cestode tissue were analysed for 14 elements using Inductively Coupled Plasma Mass Spectrometry. The elements analysed were silver (Ag), arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), potassium (K), lead (Pb), rubidium (Rb), selenium (Se), strontium (Sr), titanium (Ti) and zinc (Zn). Three of the 14 metals (Cu, Hg and Zn) were significantly greater in concentration in L. dollfusi compared with their levels in the liver, intestine and muscle of their fish host. They ranked in concentration from highest to lowest as follows: Zn > Cu > Hg. The ability of the cestode L. dollfusi to uptake metals at higher concentrations than its host warrants its consideration as a candidate for a heavy metal accumulation indicator of pollution exposure in Pacific sanddab.