Carpinteria Salt Marsh Reserve

01 Jul, 01 AM - 30 Sep, 10 AM

In 1999, the USEPA Region 9 and the SWRCB launched an initiative to develop water quality objectives to address the impacts of nutrients and biostimulatory substances in California water bodies. The initiative, termed the Nutrient Numeric Endpoint (NNE) framework, involves developing numeric endpoints that will serve as guidance in translating narrative water quality objectives for nutrients and biostimulatory substances. These endpoints are based on indicators of the ecological response to eutrophication, rather than measures of nutrient concentration or loading.Among these data gaps was the need for additional studies to identify the relationship between opportunistic marine macroalgae biomass (i.e. Ulva spp.) and adverse effects to benthic infauna on mudflats, with the intent of using this relationship to establish a numeric endpoint for regulating the effects of eutrophication in shallow enclosed bays and perennially tidal lagoons. The assumption is that reduced benthic infaunal diversity and abundance reduces the successful foraging of estuarine resident and migratory birds and estuarine fish. We will quantify: 1. Macroalgal percent cover (using a telescope method I modified) 2. Macroalgal biomass (taking samples of macroalgae) 3. Mat thickness (using rulers) 4. Taking a sediment cores for infauna, grain size and percent organic content 5. Using a sediment imager to take images of the sediment and quantify the redox discontinuity profile Macroalgal percent cover assessment: Macroalgal percent cover will be assessed at one or more sites using a telescopic technique modified from Nedwell et al. (2002). Plots up to 2500 m2 will be surveyed with either a telescope or binoculars. A visual raster across the plot and the presence and absence of macroalgae will be dictated into a digital voice recorder at the sound of a tone from a timer that beeps once per second. Macroalgal biomass: Macroalgal biomass from a minimum of one 0.25 m2 quadrat per transect. Biomass will be brought to the lab, cleaned, weighed for wet biomass and dried for dry biomass. Sediment imager: In a minimum of one site per estuary, a survey will be conducted to document the relationship between macroalgal mat thickness and benthic habitat quality. A sediment profiling camera (Bona 2006) will be used to assess the benthic habitat quality directly under and away from macroalgal mats. At intertidal sites, two- 10 meter transects will be laid down at approximately three meters from the edge of vegetation. At five randomly selected points along each transect any macroalgal mat, if present, will then be gently removed, and a visual image of the sediment profile taken at that location. Within macroalgal mats five measurements of mat depth will be taken along side the benthic profile images within a 0.25 m2 area. Subtidal plots will also be surveyed. Three-five meter transects will be laid perpendicular to the vegetation line. Profile images will be taken at three points along each transect evenly spaced with depth. At minimum, the depth to the redox potential discontinuity (RPD), a visual marker of a change from aerobic to anaerobic metabolism, will be measured. At each point that the RPD is measured macroalgal mat depth will be measured with a ruler. Sediment samples: At each location where a sediment profile image is taken, bulk sediment samples will be taken for analysis of grain size, total organic nitrogen and total organic carbon. Cores 10 cm in depth and 2.5 cm in diameter will be used to take samples. Sediment samples will be dried in an oven to record percent solids, homogenized, and processed for analysis of grain size and % TOC and TN. Infauna: Three cores will be taken from within the intertidal transects at three locations under with macroalgal mats and three from with bare sediment, side by side next to sediment profiling locations. Cores of sediment, 5 cm in diameter and 10 cm deep, will be collected. Cores will be rinsed with site water to remove sediment through a 1 mm sieve and infauna will be preserved on site with 10% buffered formalin.

Visit #22361 @Carpinteria Salt Marsh Reserve

Approved

Under Project # 22220 | Research

Macroalgal Assessment Framework to Diagnose Eutrophication in Estuaries

research_scientist - University of California, Los Angeles

Reservation Members(s)

Lauri Green Jul 1 - Sep 30, 2010 (92 days)
Lauri Green Jul 1 - Sep 30, 2010 (92 days)
Lauri Green Jul 1 - Sep 30, 2010 (92 days)
Group of 2 Volunteer Jul 1 - Sep 30, 2010 (92 days)

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Day Use Only 5 Jul 1 - Sep 30, 2010