Research

BP/FIO: Baseline for Impact Assessment of Zooplankton and Imaging Oil Droplet Detection on the West Florida Shelf. PIs: K. Daly, D. Goldgof, L. Hall. And R. Kasturi (USF) and J. Cohen (Eckerd). The monthly abundance and distribution of zooplankton are being collected along transects on the west Florida shelf and in the northern Gulf of Mexico to determine the influence of the BP oil spill on zooplankton communities. Zooplankton are a critical component of marine ecosystems, given that the larval stages of commercially and recreationally important shellfish and fish are part of the zooplankton community. A zooplankton camera imaging system (SIPPER) is being used to assess zooplankton and to detect oil droplets. The PICES image pattern recognition software will be further developed to allow more accurate detection and classifications of oil droplets and zooplankton taxa. The lower trophic levels of the food web are particularly sensitive to oil. Controlled laboratory experiments will be conducted to assess mortality and sublethal effects of BP oil and disspersant on zooplankton behavior.

NSF: Collaborative: Benthic-pelagic coupling in an intact ecosystem: The role of top predators in McMurdo Sound. NSF/OPP 0944511. This project will focus on food web interactions of three abundant predators, Adélie penguins, minke whales, and the fish-eating “Ross Sea” killer whales, all of which exert foraging pressure on their main prey, crystal krill (Euphausia cyrstallorophias) and silver fish (Pleuragramma antarcticum) in McMurdo Sound. Annually, an icebreaker cuts open a channel through fast ice to McMurdo Station (20 km from ice edge), providing a large scale “natural” experiment with which we can investigate predator effects on prey distributions. We will deploy a video- and acoustic-capable ROV with environmental sensors through Jiffy-drilled holes in the fast ice to quantify the abundance and distribution of phytoplankton, sea ice biota, and prey before the icebreaker arrives, as well as after when the risk of predation by large predators increases.

NSF: EAGER: Discovery of viruses infecting marine Copepoda. Co-PIs M. Breitbart, K. Daly, I. Hewson. NSF/OCE 1030338. Two decades of research on marine viruses have demonstrated their profound effects on all levels of marine life from bacteria to whales. The majority of marine virus studies have focused on infection of microorganisms, particularly heterotrophic prokaryotes and eukaryotic phytoplankton. Despite the ecological importance of zooplankton, virtually nothing is known about the impact of viruses on the most abundant zooplankton group – the copepods. We will prospect for novel viruses in dominant,
ecologically important copepod species using metagenomic sequencing approaches and through amplification and sequencing of genes conserved among groups of invertebrate viruses. Active viral infection will be distinguished from viral presence through electron microscopy, in situ hybridization, and viral gene expression assays. The viral load, prevalence, and tissue specificity will be examined through a combination of molecular methods, microscopy, and experimental manipulations.

US GLOBEC Synthesis and Modeling Phase. NSF/OPP-0814405. We will collaborate with 21 interdiciplinary investigators from academia, NOAA/NMFS, and the British Antarctic Survey to examine the extent to which marine food webs that support fisheries are controlled by bottom-up (physical processes) versus top down (predation, fishing) forcing. Food web models will be developed for the Southern Ocean. A comparative analysis of models for the three US GLOBEC regional field programs (Southern Ocean, Georges Bank, NE Pacific) will be evaluated, the skill of the models will be assessed, and diagnostic measures will be developed. /http://www.usglobec.org/

Zooplankton in the Redoxcline: Impact on Biogeochemical Cycling. NSF/OCE 0526545. The eastern tropical Pacific Ocean has the world's largest persistent oxygen minimum zone (OMZs). OMZs appear to be sensitive to climate variability and ocean acidification and appear to be expanding due to a warming ocean. Low dissolved oxygen influences marine biogeochemical cycles and, therefore, strongly impacts marine carbon and nitrogen cycles. Strong vertical oxygen gradients also exert a considerable influence on organism distributions. Two cruises during October/November 2007 and December 2008/January2009 allowed us to investigate food web structure and initial studies of the role of crustacean zooplankton in the production and transformation of particulate and dissolved material. The distribution and feeding by microzooplankton and mesozooplankton were investigated. In addition, egestion and metabolic byproducts of dominant mesozooplankton were assessed. One of our primary hypotheses is that zooplankton graze on chemosynthetically-produced biomass at the upper and lower oxyclines of the Oxygen Minimum Zone and, in doing so, provide a mechanism by which slowly sinking bacterial aggregates are packaged into more rapidly sinking fecal pellets (or aggregates). This would provide a mechanism for transporting part of the chemoautotrophic biomarker signal to the seafloor. This work will contribute to our knowledge of the role of mesozooplankton in biogeochemical cycles, especially in relation to how processes may be modified in regions of suboxic environments and strong redox gradients. Further iinformation on our cruise may be viewed at http://etpcruise.blogspot.com/. In addition, zooplankton images obtained from vertical profiles of the SIPPER imaging system may be viewed at http://www.marine.usf.edu/sipper/.

ONR: Development and Evaluation of High Resolution Ocean Imaging Systems. PIs: K. Daly and G. Gonzalez. Next generation of the SIPPER imaging system.

ONR: Mobile, Autonomous and Remote Controlled Observation Node (MARCON) For Ecosystems Adaptive Sampling and Persistent Observations . Co-PIs D. Fries & K. Daly.