Life Sciences Commons^™

Histology And Ultrastructure Of Montastraea Cavernosa And Porites Astreiodes During Regeneration And Recruitment: Anthropogenic Stressors And Transplant Success, Dorothy-Ellen A. Renegar

D. Abigail Renegar

Corals combine photosynthesis and calcification in an intricate and delicately balanced relationship to form large biomineralized structures that are dominant features of tropical coastlines worldwide. Coral reefs have great scientific and economic importance but have recently experienced widespread decline attributed to increasing anthropogenic pressure on reef systems. Physical damage events, such as ship groundings, when coupled with existing nutrient stress and changing global climate present a poor outlook for successful natural recovery of reef communities. The main goal of the proposed research is to better understand how environmental factors, both local and global, affect the coral holobiont and influence overall …

Reproductive Parameters Of Coastal Pelagic Fishes, Sonia Ahrabi-Nejad, David W. Kerstetter, Patricia Blackwelder, Dorothy-Ellen A. Renegar

D. Abigail Renegar

The ability to manage a fish stock relies on an understanding of life history characteristics and basic biology of the species. Numerous age-growth studies are facilitated by the relative ease of ageing fishes through hard-part analyses. Determining reproductive parameters for fish populations is just as important for stock assessments and management, and histological examination of gonads provides the most accurate determination of fecundity and spawning periods. However, research in this area is limited. Coastal pelagic fishes are often targeted commercially and recreationally due to their easy access by private vessels. The objective of this study is to provide baseline data …

Ultrastructural And Histological Analysis Of Dark Spot Syndrome In Siderastrea Siderea And Agaricia Agaricites, Dorothy-Ellen A. Renegar, Patricia Blackwelder, J. D. Miller, D. J. Gochfeld, Alison L. Moulding

D. Abigail Renegar

Dark Spot Syndrome (DSS) typically manifests in scleractinian corals as lesions of varying color, size, shape and location that can result in skeletal changes and tissue death. A causative agent for DSS has not yet been identified. The objective of this study was histological and ultrastructural comparison of the cellular and skeletal characteristics of DSS-affected and healthy Siderastrea siderea and Agaricia agaricites. The greater resolution possible with transmission electron microscopy (TEM) revealed microbial activity and tissue changes not resolvable utilizing histology. DSS-affected tissue had less integrity, with increasing cellular degradation and vacuolization. A high concentration of electron dense inclusions, …

Effect Of Nutrient Enrichment And Elevated Co2 Partial Pressure On Growth Rate Of The Zooxanthellate Coral Acropora Cervicornis., Dorothy-Ellen A. Renegar

D. Abigail Renegar

Trends of increasing coastal eutrophication and atmospheric pCO2 require investigation to predict the combined effects on coral and reef condition and growth. Increases in nutrient concentrations have been observed over the past several decades in a number of reef systems, and it has been predicted that this will adversely affect coral growth rates. The species targeted by this research, Acropora cervicornis, is among the most important reef-builders in the Caribbean and has suffered widespread mortality in southern Florida. Approximately 192 branch tips were harvested from two local populations of A. cervicornis and maintained in the laboratory, where the growth rate …

Coral Ultrastructural Response To Elevated Pco2 And Nutrients During Tissue Repair And Regeneration, Dorothy-Ellen A. Renegar, Patricia Blackwelder, Alison L. Moulding

D. Abigail Renegar

Corals and coral reefs have recently experienced widespread decline attributed to anthropogenic pressure on reef systems. Studies have demonstrated that nutrient and pCO2 stress effect coral growth and calcification, but study of specific effects on coral tissue is lacking. The objective of this research was to examine wound healing in corals and how it is affected by exposure to elevated nutrients and pCO2. Coral tissue repair and regeneration during wound healing in Montastraea cavernosa and Porites astreoides were assessed histologically and ultrastructurally by examining colony fragments exposed to elevated nitrate, phosphate, and pCO2. In M. cavernosa, tissue repair was facilitated …

Acute And Sub-Acute Toxicity Of The Polycyclic Aromatic Hydrocarbon 1-Methylnaphthalene To The Shallow-Water Coral Porites Divaricata: Application Of A Novel Exposure Protocol, Dorothy-Ellen A. Renegar, Nick Turner, Bernhard Riegl, Richard E. Dodge, Anthony H. Knap, Paul Schuler

D. Abigail Renegar

Previous research evaluating hydrocarbon toxicity to corals and coral reefs has generally focused on community-level effects, and results often are not comparable between studies because of variability in hydrocarbon exposure characterization and evaluation of coral health and mortality during exposure. Toxicity of the polycyclic aromatic hydrocarbon 1-methylnaphthalene to the coral Porites divaricata was assessed in a constant exposure toxicity test utilizing a novel toxicity testing protocol uniquely applicable to shallow-water corals, which considered multiple assessment metrics and evaluated the potential for post-exposure mortality and/or recovery. Acute and subacute effects (gross morphological changes, photosynthetic efficiency, mortality, and histologic cellular changes) were …

The Shellfish Corner: The Luther H. Blount Shellfish Hatchery Of Rhode Island, Michael A. Rice

Michael A Rice

Rapid Recovery Of A Coral Reef At Darwin Island, Galapagos Island, Peter W. Glynn, Bernhard Riegl, Adrienne M. S. Correa, Iliana B. Baums

Bernhard Riegl

Surveys at Darwin Island in 2006 and 2007 have demonstrated that this northernmost Galapagos Islands coral reef has recovered significantly since the 1982-3 El Nino event. When first surveyed in 1975, this structural reef exhibited actively accreting frameworks of pocilloporid and poritid corals. The coral suffered severe mortality in 1983, resulting in the near total loss of pocilloporids and extensive partial mortality of poritid corals. Large sections of the reef had not recovered by 1992 and dead frameworks were subject to bio-erosion, although small numbers of sexual recruits of pocilloporid corals and numerous recruits plus regenerating patches of Porites lobata …

Environmental Impacts Of Dredging And Other Sediment Disturbances On Corals: A Review, Paul. L. A. Erftemeijer, Bernhard Riegl, Bert W. Hoeksema, Peter A. Todd

Bernhard Riegl

A review of published literature on the sensitivity of corals to turbidity and sedimentation is presented, with an emphasis on the effects of dredging. The risks and severity of impact from dredging (and other sediment disturbances) on corals are primarily related to the intensity, duration and frequency of exposure to increased turbidity and sedimentation. The sensitivity of a coral reef to dredging impacts and its ability to recover depend on the antecedent ecological conditions of the reef, its resilience and the ambient conditions normally experienced. Effects of sediment stress have so far been investigated in 89 coral species (∼10% of …

Fallout Pu In Annual Bands From The Coral Montastrea Annularis, St. Croix, Usvi, Larry K. Benninger, Richard E. Dodge

Richard Dodge

Coralline aragonite is known to incorporate certain minor or trace constituents from seawater (U, Sr, Ra, 210Pb) with essentially constant discrimination relative to Ca. Noshkin and others [Limnol. Oceanogr. 20(1975)729] reported that Pu was also incorporated with constant discrimination and suggested the use of annual bands in corals as a recording indicator of ambient seawater Pu. We report preliminary results of a study of fallout Pu in annual bands of Montastrea annularis from St. Croix, U.S.V.I. Along with fallout Pu we have determined: U, 232Th, 228Ra (as 228Th) and 210Pb (as 210Po). These determinations are used to test for constancy …

Coral Fluorescence Records Everglades Hydrology: 1918-1983, T. J. Goreau, Richard E. Dodge, P. D. Goreau, J. Dunham

Richard Dodge

An ultraviolet laser was used to study the fluorescence spectrum of coral skeletons. Montastrea annularis heads growing near the mouth of the New River Canal, Florida, had unusual three-part growth and fluorescence records:

1. 1918-1944. High growth, annual fluorescence peak.
2. 1945-1969. Low growth, high fluorescence, except during drought years
3. 1970-1983. High growth, annual fluorescence peak.

The first change followed opening of the New River Canal to drain the Everglades-Lake Okeechobee Agricultural Area for sugar cane cultivation. In 1969 canal flows were sharply reduced, and urban and agricultural waste waters pumped into diked conservation areas in order to increase infiltration into a …

Burrow Morphology And Behavior Of The Mud Shrimp Upogebia Omissa (Decapoda: Thalassinidea: Upogebiidae), Vania Rodrigues Coelho, Roland Arthur Cooper, Sergio De Almeida Rodrigues

Vânia Coelho

The burrow morphology, burrowing behavior and feeding mechanisms of the thalassinidean shrimp Upogebia omissa were studied. Twenty burrow casts were made in situ with epoxy resin, and an overall 'Y' shape was most frequently observed. Several burrows consisted of a single, oblique tunnel; burrow diameter was positively correlated with burrow length, maximum depth and distance between openings. Additionally, burrow length was positively associated with maximum depth, indicating that as burrow length increased burrow depth increased; i.e. burrows spread vertically rather than horizontally. Total sediment displacement by the burrows accounted for 2.6 % of sediment to a depth of 30 cm. …

The Shellfish Corner: Aquaculture Of Exotic Shellfish Species, Michael A. Rice

Michael A Rice

Giants Among Micromorphs: Were Cincinnatian (Ordovician, Katian) Small Shelly Phosphatic Faunas Dwarfed?, Benjamin F. Dattilo, Rebecca L. Freeman, Winfried S. Peters, William P. Heimbrock, Bradley Deline, Anthony J. Martin, Jack W. Kallmeyer, Jesse Reeder, Anne Argast

Winfried S. Peters

The Shellfish Corner -- Water Quality And Culture Of Shellfish In Prohibited Waters, Michael A. Rice

Michael A Rice

Notes On The Identification And Distribution Of The Exotic Western Hemisphere Mussel, Mytella Charruana D'Orbigny 1846, In The Estuaries Of Pangasinan, Philippines., Michael Rice, Paul Rawson, Westly Rosario

Michael A Rice