Greg Tolley, Ph.D.

University of South Florida

Ph.D.

Marine Science

Marshall University

B.S.

Zoology

Water Security

Save Our Water: Market Watch Summit  Fort Myers, Florida

2018-05-11

Oyster-reef restoration as a means of enhancing estuarine ecosystem function

Florida Oyster-reef Restoration Summit  St. Petersburg, Florida

2007-03-15

Managing freshwater inflow to optimize prey production for young estuarine-dependent fishes in the Caloosahatchee Estuary

Coastal and Estuarine Research Federation  Daytona Beach, Florida

2011-11-06

Research programs at Florida Gulf Coast University related to the study of coastal watersheds in Southwest

U.S. Environmental Protection Agency

Jul 2005-Jun 2007

Long term monitoring of oysters (crassostrea virginica) in Southwest Florida: oyster monitoring in the Caloosahatchee River and Estuary, Florida

South Florida Water Management District

2010-2015

Freshwater inflow and utilization of the estuarine tributaries of Estero Bay

South Florida Water Management District

Sep 2004-Feb 2007

Recruitment of the crabs Eurypanopeus depressus, Rhithropanopeus harrisii, and Petrolisthes armatus to oyster reefs: the influence of freshwater inflow

Tolley, Stephen Gregory, Bethany Bachelor Brosious, and Ernst Bryan Peebles.

2013

Oyster reefs provide structural habitat for resident crabs and fishes, most of which have planktonic larvae that are dependent upon transport/retention processes for successful settlement. High rates of freshwater inflow have the potential to disrupt these processes, creating spatial gaps between larval distribution and settlement habitat. To investigate whether inflow can impact subsequent recruitment to oyster reefs, densities of crab larvae and post-settlement juveniles and adults were compared in Estero Bay, Florida, over 22 months (2005–2006). Three species were selected for comparison: Petrolisthes armatus, Eurypanopeus depressus, and Rhithropanopeus harrisii. All are important members of oyster reef communities in Southwest Florida; all exhibit protracted spawning, with larvae present throughout the year; and each is distributed unevenly on reefs in different salinity regimes. Recruitment to oyster reefs was positively correlated with bay-wide larval supply at all five reefs examined. Species-specific larval connectivity to settlement sites was altered by inflow: where connectivity was enhanced by increased inflow, stock–recruitment curves were linear; where connectivity was reduced by high inflows, stock–recruitment curves were asymptotic at higher larval densities. Maximum recruit density varied by an order of magnitude among reefs. Although live oyster density was a good indicator of habitat quality in regard to crab density, it did not account for the high variability in recruit densities. Variation in recruit density at higher levels of larval supply may primarily be caused by inflow-induced variation in larval connectivity, creating an abiotic simulation of what has widely been regarded as density dependence in stock–recruitment curves.

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Acute response of the estuarine crab Eurypanopeus depressus to salinity and desiccation stress

Horn, Julie Van, and S. Gregory Tolley.

2009

Hemolymph osmolality changes following exposure to abrupt salinity change in the range of 5–40 ppt (T=26∘C⁠, full air saturation) and upon exposure to air (T=23∘C,r.h. =30/ were investigated in the flatback mud crab Eurypanopeus depressus (Smith, 1869), a dominant species on oyster reefs in Southwest Florida. During salinity trials, hemolymph osmolality of E. depressus ranged from 751±123 mOsmol kg−1 at 5 ppt (214±32 mOsmol kg−1) to 1188±81 mOsmol kg−1 at 40 ppt (1188±29 mOsmol kg−1)⁠. In the salinity range of 5–15 ppt E. depressus exhibited a hyperosmotic pattern of osmoregulation while at 30 and 40 ppt it conformed. In all cases stable hemolymph osmotic concentration was reached in less than 24h⁠. During desiccation trials, hemolymph osmolality of E. depressus ranged from 971±121 mOsmol kg−1 for unexposed crabs to 1132±169 mOsmol kg−1 after 90min of exposure. The information obtained from this study adds to knowledge of crustacean stress physiology and may give a clearer picture of the important factors involved in population distribution and the consequences of multiple stressors that may affect the crabs or their oyster-reef habitat.

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The role of oysters in habitat use of oyster reefs by resident fishes and decapod crustaceans

Tolley, SG & AK Volety

2005

To assess the role of live oysters in providing habitat, community metrics of resident fishes and decapod crustaceans were compared among 3 habitat treatments: live oyster clusters; cleaned, articulated shell and sand bottom. Sampling was conducted during three seasonally wet and three seasonally dry months using 1-m2 lift nets deployed on an intertidal oyster reef in the Caloosahatchee estuary, Florida. Metrics used to assess relative habitat value included organism density, biomass and species richness. Species-specific comparisons were also made. Results indicate that organism density, biomass and richness were all greater for treatments with shell (live oyster clusters or cleaned, articulated shell) compared with the sand-bottom (no-shell) treatment. Two patterns emerged from species-specific comparisons: (1) species found in live and articulated shell (e.g., flatback mud crab, green porcelain crab) might require shelter; and (2) species found in association with articulated, cleaned shell (i.e., frillfin goby) might use empty oyster boxes for spawning substrate. There was little evidence to suggest that any of the decapods or fishes present were specifically selecting habitat with living oysters present.

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