Diel Activity Patterns, Space Utilization, Seasonal Distribution and Population Structure of the Yellow Stingray, Urobatis jamaicensis (Cuvier, 1817) in South Florida with Comments on Reproduction.

The yellow stingray, Urobatis jamaicensis is the most common elasmobranch in the coastal waters of Southeast Florida. Despite their common occurrence the ecology of yellow stingrays remains poorly understood. In particular, yellow stingray daily movements, space utilization, seasonal distribution and population structure have not been described. This study was conducted to address the lack of knowledge of these fundamental life history parameters and to provide further information on the ecology of U. jamaicensis in coastal waters of Broward County, Florida. The activity patterns and space utilization of U. jamaicensis were assessed by manual tracking with ultrasonic telemetry. Telemetry tracking of 17 stingrays was conducted from January 1998 to September 2001 with data presented on eight individuals tracked for a full diel cycle (24 h). Tracking data was analyzed with the Animal Movement Analysis Extension (AMAE) in Arcview® GIS to provide graphical representation of observed movements within the complex series of reef terraces and hardbottom communities of Broward County. Bottom topography had considerable influence on the space utilization of stingrays and observed movements varied with location in relation to proximity from the reef edge/sand interface. Movement was intermittent throughout the day, but displayed a highly significant increase during the nocturnal and crepuscular phases in comparison to diurnal movements. Nearly all stingrays demonstrated confined movements and indicated strong site fixity, which may imply the existence of home ranging behavior. The 95% (total 24h activity space) and the 50% (core area) Kernel Utilization Distributions (KUD) were constructed to visually display the shape and size of activity spaces. The data was pooled together for the eight individuals tracked for a full diel cycle and divided into four 6-h shifts. Statistically significant larger activity spaces for both the 95% KUD and the 50% KUD were observed during the nocturnal activity phase. Seasonal distribution was assessed to determine animal residency within the study site and ascertain the occurrence and temporal patterns of onshore/offshore movements. Stationary visual fish census techniques (point counts) from several studies conducted in Broward County from January 1998 to December 2003 were combined to determine the level of abundance across three reef tracts, throughout the entire length of the county. Data was tested for monthly and seasonal differences and for variation between reefs. Analysis of seasonal distribution established population residency is year-round with no indication of offshore emigration associated with a temperature preference. Population structure analyses were conducted to determine the sex ratio and size distribution of U. jamaicensis to examine any potential gender segregation or ontogenetic partitioning. The sex ratio was compared for differences monthly, seasonally and between reefs for expected vs. observed frequencies. Only spring observations (March, April, May) evidenced a statistically significant difference from a 1:1 ratio, where females dominated the inshore observations 20F:8M. Average size of both genders was 333mm TL, however, females dominated the larger size classes (\u3e350mm TL). Few neonates were observed during this study with most observations occurring in shallow inshore water (depth), suggesting a nearshore nursery. Increased abundance and presence on the offshore reef among intermediate size classes (250-299mm to 300-349mm) suggests a potential ontogenetic shift to deeper water. Observations on the seasonal patterns of the reproductive condition of female yellow stingrays are also provided

Growth and Survivorship of Scleractinian Coral Transplants and the Effectiveness of Plugging Core Holes in Transplant Donor Colonies

Replicate scleractinian coral transplants were obtained from the species Meandrina meandrites and Montastrea cavernosa on a natural reef, off Dania Beach, Florida, using a hydraulic drill fitted with a 4 in. (~10 cm) core barrel. The transplants were fixed to Reef Ball™ substrates using an adhesive marine epoxy. Drill holes in the donor corals (core holes) were filled with concrete plugs. Control corals, of comparable size to both donor colonies and transplant corals, were monitored for comparison. Transplant corals, donor corals, and controls on the natural reef were monitored for growth and survivorship. Core holes were monitored for tissue regrowth over the surface of concrete plugs. Growth during the transplantation project was defined as an increase in surface area of tissue and skeleton. Growth was monitored on a quarterly basis using photographic techniques. Meandrina meandrites transplants experienced greater mortality and significantly less growth than M. cavernosa transplants. No significant difference in the change in percent tissue coverage between both species of donor corals or between their respective controls was determined. The process of filling core holes in donor colonies with concrete plugs was effective, however, tissue did not completely regenerate over the surface of plugs in either species over the relatively short 15-month observation period. Results of this study indicate that species selection is an important factor in the success of coral transplantation

The Yellow Stingray, Urobatis jamaicensis (Chondrichthyes Urotrygonidae): A Synoptic Review

The yellow stingray, Urobatis jamaicensis (Cuvier) has been the subject of a multitude of diverse studies on its natural history, morphology, and physiology. We have attempted here to briefly review all the studies on U. jamaicensis both published and unpublished with the goal of providing comparative information for researchers working on related species as well as to highlight areas of research requiring further investigation in this one

Recovery of Injured Giant Barrel Sponges, Xestospongia muta, Offshore Southeast Florida

Giant barrel sponges, Xestospongia muta, are abundant and important components of the southeast Florida reef system, and are frequently injured from anthropogenic and natural disturbances. There is limited information on the capacity of X. muta to recover from injury and on methods to reattach X. muta fragments. In late 2002, hundreds of barrel sponges offshore southeast Florida (Broward County) were accidentally injured during an authorized dredging operation. In early 2003, two to three months post-injury, 93% of 656 assessed injured sponges appeared to be recovering. In 2006, three years post-injury, nearly 90% of 114 monitored sponges continued to show signs of recovery. Growth rates were estimated by measuring sponge height above visual injury scars and ranged from 0.7 cm yr- ¹ to 6.0 cm yr- ¹. Information on the artificially reattached fragments is limited but did show that X. muta fragments can reattach. This study provides evidence that X. muta in southeast Florida can naturally recover. Details on sponge size class associated recovery processes and growth were not collected due to event associated legal issues limiting the study. Studies to determine detailed growth rates and recovery success for different injury and restoration scenarios will further facilitate restoration decision making by resource managers

Growth and Survivorship of Stony Coral Meandrina meandrites and Montastrea cavernosa Transplants to an Artificial Reef Environment: A Work in Progress

Reef Ball Deployment: In November of 2000, 160 concrete Reef BallTM modules (1.22m wide x 0.9m high) were deployed, at a depth of approximately 15 meters, between the Second and Third Reef tracts off Dania Beach, FL (Figures 1 and 2). The Reef Balls were grouped into 40 quads, with each quad containing four individual Reef Balls. One modified Reef Ball from each quad was designated as the ‘transplant’ ball, and was used as the receptacle for the coral transplants. The other three balls in each quad are part of a more comprehensive study. This multifactorial study is examining the effects of reef structure on fish assemblages, the effects of coral larval attractants on coral recruitment, and the interaction between fish assemblages and coral recruitment. The coral transplants are one such ‘coral larval attractant’ being examined. Coral transplants, and the donor colonies from which they were obtained, are being monitored for growth and survivorshi

Techniques for Restoring Gorgonians to Coral Reef Injury Areas

Great attention and energy has been spent investigating reattachment techniques for dislodged and fragmented scleractinian corals; however there has been a lack of controlled experimentation on how to restore dislodged gorgonians following a disturbance event, such as a ship grounding. Unfortunately, reef damage events occur frequently off southeast Florida. As an example, since 1998 at least five freighters have grounded on the reefs near Ft. Lauderdale, Broward County. These freighters dislodged many scleractinian and gorgonian corals and often destroyed thousands of square feet of reef habitat. After these events, restoration efforts concentrated on stabilizing loose debris and rubble, and reattaching scleractinian coral fragments and dislodged colonies. Although southeast Florida’s reefs are dominated by gorgonian corals, which are also sheared from the reef when ships ground, restoration efforts generally do not place much emphasis on reattaching dislodged gorgonian colonies. In order to determine effective techniques for restoring gorgonian populations, 94 gorgonian clippings were transplanted to a reef area in Broward County, Florida in June 2004. The 15-cm clippings were cut from naturally occurring loose colonies of Pseudopterogorgia americana, Plexaura flexuosa and Muricea muricata, common gorgonians in the southeast Florida reef system. Half of these clippings were attached to the reef substrate using Portland II cement; the other half were transplanted to the reef with two-part marine epoxy. These clippings will be monitored quarterly for a minimum of one year to measure growth and health, and whether the colonies form attachments to the reef over the cement or epoxy. Clipping growth data will be compared to control, 15-20 cm naturally attached, colonies of the same species to determine whether transplant growth is similar to naturally occurring small gorgonian colonies. Data will also be collected on loose control colonies, which are tethered to small pins in the substrate. These controls will indicate whether dislodged colonies left loose on the reef will die, or whether they will reattach and continue to grow. The goal of this study is to determine effective techniques to restore gorgonian populations. This study aims to create a protocol that resource managers and scientists may follow when determining the most effective way to restore gorgonians to reef habitats following events such as ship groundings. This protocol will take into consideration the condition of each gorgonian colony and the resources available (equipment, money, and time) for restoration

Coral Reef Ecosystem Restoration Off Southeast Florida

Significant coral reef community development along the eastern shelf of the United States continues northward of the Florida Keys through Miami-Dade, Broward, Palm Beach, and Martin Counties, Florida (to Latitude 27° N). These Southeast Florida high-latitude coral communities have approximately 30 species of stony corals, stony coral coverage of 2-3%, and a diverse assemblage of reef gorgonians, sponges, and fishes. This system lays within 3 km of the coast offshore a highly urbanized area comprising a population of over 5 million people (the population of Broward County alone exceeds 1.7 million). These reefs are important economic assets: a 2001 economic assessment estimated the annual reef input for Miami-Dade, Broward, and Palm Beach Counties at 5.8 billion dollars. Potential impacts to the system include those from commercial and recreational fishing and diving, sewer outfalls, marine construction activities (fiber optic cables, channel dredging, gas pipe lines), and major shipping ports and ship groundings. Southeast Florida has three major shipping ports; Port of West Palm Beach, Port Everglades (Broward County), and the Port of Miami. At Port Everglades alone, over 5,300 ships call on an annual basis. This heavy ship traffic very near and within a coral reef system has resulted in nearly one ship grounding per year offshore Broward County since the early 1990’s. Nearly all reef damage events involve some level of injury assessment, triage and restoration, and monitoring. Triage generally involves the uprighting and caching of dislodged and fragmented stony coral colonies. At a minimum, restoration activities include the reattachment of these stony coral colonies. Restoration may also include the reattachment of dislodged octocorals and sponges and the removal of rubble generated by the damage event. This work summarizes restoration activities and monitoring results from several representative reef damage events that have occurred offshore Broward County, Florida. Discussion will include the effectiveness of past and current restoration and monitoring activities. Recommendations for improved restoration activities and more effective recovery monitoring will also be discussed

Change and Aging Senescence as an adaptation

Understanding why we age is a long-lived open problem in evolutionary biology. Aging is prejudicial to the individual and evolutionary forces should prevent it, but many species show signs of senescence as individuals age. Here, I will propose a model for aging based on assumptions that are compatible with evolutionary theory: i) competition is between individuals; ii) there is some degree of locality, so quite often competition will between parents and their progeny; iii) optimal conditions are not stationary, mutation helps each species to keep competitive. When conditions change, a senescent species can drive immortal competitors to extinction. This counter-intuitive result arises from the pruning caused by the death of elder individuals. When there is change and mutation, each generation is slightly better adapted to the new conditions, but some older individuals survive by random chance. Senescence can eliminate those from the genetic pool. Even though individual selection forces always win over group selection ones, it is not exactly the individual that is selected, but its lineage. While senescence damages the individuals and has an evolutionary cost, it has a benefit of its own. It allows each lineage to adapt faster to changing conditions. We age because the world changes.Comment: 19 pages, 4 figure