Development of an Underwater Infrared Camera to Detect Manatees

In calendar year 2004, watercraft related mortality was the second leading cause of death of the Florida manatee (Trichechus manatus latirostris) accounting for 25% of total known manatee deaths. In an attempt to reduce this significant cause of manatee mortality, the Florida Fish and Wildlife Research Institute has instituted two rounds of Manatee Avoidance Technology grants. Herein I report the results of an evaluation of the ability of underwater infrared video cameras to detect captive manatees and other non-living targets. If such cameras could detect manatees at sufficient distances, they could be mounted in the bows of watercraft and the resultant images could be projected at the helm of the vessel, enabling the vessel operator to reduce speed, take evasive action, or both. Two types of cameras were examined: 1) A SeaView underwater video camera system from PowerLinx, St. Petersburg, FL, and 2) An Atlantis underwater camera system (AUW-535C) from JJC Communications, Inc., Englewood, NJ. Preliminary investigations of the ability of these cameras to detect small objects indicated that their resolution decreased with distance from the target and depth, with the highest resolution closest to the target and near the surface. However, even at optimal depth, the maximum detection distance for the small target with the SeaView Camera was less than 3 m, and less than 5.5 m for the Atlantis camera. Thus, the Atlantis camera was marginally better able to detect the small target than was the SeaView camera. The cameras were then tested on a plywood silhouette of a manatee placed vertically in the water. In this case the detection distance increased with depth, being greatest at a depth of 2 m, but in no case was the detection distance greater than 5 m. As before, the Atlantis camera was marginally better able to detect the plywood manatee silhouette than was the SeaView camera. The cameras were then tested using living captive manatees at the Lowry Park Zoo (LPZ). Due to the clarity of the water at LPZ, manatees were visualized by both cameras at a distance of up to approximately 15 m, independent of depth. The Atlantis camera was better able to detect the living manatees than was the SeaView camera. Because these cameras emit infrared light in order to enhance their water penetration and image detection, there was some concern on the effect of this light on the manatees. However, the infrared light emitted by the cameras appeared to elicit no alarm or aversion from the manatees, and in fact seemed to increase their curiosity about the cameras and to attract them to the cameras. The larger size of the Sea View camera also appeared to draw the attention of the animals to the camera, and to prompt them to approach it in a playful manner. Over the course of this investigation, one NSU Oceanographic Center graduate student has started on a thesis research project. The results of this investigation were presented at the second Florida Marine Mammal Health Symposium, held 7-10 April 2005 in Gainesville, FL (Wright and Keith 2005). The currently available underwater infrared camera technologies evaluated here do not seem to have sufficient detection distances to enable their immediate incorporation into a operator manatee awareness system, in order to utilize the cameras as described above. Our future plans are to approach the manufacturers of these cameras to determine if the technology can be enhanced to enable the cameras to detect manatees at sufficient distance to enable them to be used as described above

Critical Review of the Literature on Marine Mammal Population Modelling

A comprehensive literature review and modeling effort have been conducted in order to determine which vital rates are most important to determining the growth and sustainability of marine mammal populations. Also addressed are the impacts of life-history, ecological, and genetic variation on vital rates and population sustainability and how much each vital parameter can change before a change in population trend would be expected. Additionally, the influence of ecological energetics and foraging strategies on vital rates and their limits of sustainable change are examined, and the nature of how an increase in sound in the marine environment might influence marine mammal behavior, and thus life functions, vital rates and population sustainability is explored. An analysis of the elasticity and sensitivity of marine mammal population models suggests that: 1) Most whale populations appear to be most sensitive to changes in adult female survival and least sensitive to calf survival. 2) Most whale populations appear to be secondarily sensitive to changes in juvenile survival and growth. 3) Most whale populations, with the exception of North Atlantic right whales (Eubalaena glacialis), appear to be insensitive to changes in fecundity at any age. 4) Adult female whales may be sensitive to changes in foraging success that limit their ability to acquire sufficient body stores of energy to sustain gestation, parturition, and lactation. 5) These results are similar to those arising from studies of non-mammalian marine predators as well as terrestrial vertebrates with similar life history characteristics. A risk assessment of the potential impacts of ocean noise on marine mammal populations based on modeling marine mammal populations suggests that: 1) Any increase in anthropogenic noise in the marine environment that reduces adult female survival, for whatever reason, is to be avoided, 2) It may be impossible to detect the impact of a change in a population vital rate on population growth because such a change may be less than the confidence interval around the estimates of the rate of growth of most marine mammal populations. 3) Sensitivity and elasticity analyses of marine mammal population models predict linear changes in marine mammal population growth rates caused by linear changes in vital rates, and do not indicate thresholds within which vital rates can change without altering population growth rates. Future research efforts should focus on the following: 1) The relationship between noise in the marine environment and adult female and juvenile survival. 2) To increase the precision and decrease the uncertainty of marine mammal population and vital rate estimates. 3) Improving the concept of potential biological removal (PBR) to reflect cumulative mortality impacts and to incorporate the effects of noise. 4) Increasing knowledge of marine mammal activity budgets seasonally and in different parts of their habitats. 5) To more fully elucidate the roles of marine mammals in their ecosystems, and their importance as sentinels of ecosystem health. 6) To exhaustively utilize existing data and models because of the cost and difficulty of gathering more data

Boater Manatee Awareness System

A variety of see-in-the-dark technologies have been evaluated with the objective of adapting them to detect Florida manatee (Trichechus manatus latirostris) aggregations in specific highuse areas, such as warm water refuges in the winter time. Once it is possible to passively detect manatee aggregations in these sites, the construction of boater awareness signs that would indicate how many manatees are in the area, on a real-time basis, is envisioned. The contention is that boaters would be more likely to obey speed restrictions if these restrictions were accompanied by this type of information. The ability to do this also might enable such speed restrictions to be more flexible, and only enforced when manatees are actually present. This would make such speed restrictions more palatable to boaters. The three technologies that I have examined are: (1) infrared cameras that detect infrared (heat) radiation emitted by all warm objects, (2) night-vision viewers that emit infrared radiation and then use the reflected radiation to generate an image, and (3) “night-shot video cameras that also emit infrared radiation and then record the images generated by the reflected radiation. Each of these technologies have advantages and disadvantages. The true infrared cameras provide the best images, at least in air. Water absorbs most infrared radiation, and so these cameras cannot penetrate water to image submerged objects such as manatees. I knew this prior to beginning my investigations, but thought that this technology might be able to detect manatee exhalations, which I anticipated would be warmer than the ambient air. It turns out that this is not the case, in that manatees appear to exhale air from their nostrils at close to ambient temperature. It has long been known that desert animals, and other marine mammals such as northern elephant seals (Mirounga angustirostris) also do this, and that this constitutes a water conservation mechanism. However, these cameras can detect the actual nostril openings of the manatees. Their images can also be sharply focused, and are not diminished by ambient light sources such as streetlights. This technology can also be used during daylight hours. The major drawback of these cameras is their expense, $15-30,000.00, and the need for a portable video recorder (also expensive) to capture images. Because of the limited success of the infrared cameras, I also evaluated a night-vision scope. These are much less expensive,$300-500.00, which makes their deployment more economically feasible. They also appear to be able to penetrate the water to a depth of 0.5-1.0 meter. However, the images generated by this technology are of poorer quality, and this quality is deleteriously impacted by other ambient light sources. In addition, these scopes cannot be used during daylight hours. Capturing images on film also requires a 35 mm camera and adaptor. I also found that many current models of handy-cam videocassette recorders have a nightshot capability, that utilizes a similar technology to the night-vision scopes, and can be purchased for $300-500.00. I anticipated that the ability to directly record the images detected by the camera would be a distinct advantage, as would the ability to switch from regular daytime video recording to nighttime video recording with the flip of a switch. However, the drawback of these video cameras is that they do not penetrate the water as well as the night-vision scopes, resulting in poor quality video images. All of these technologies have their advantages and disadvantages which limit their application to the proposed boater awareness system. I believe that the night-vision technology might be best adapted to the system that I envision, but this would require more time and funding to fully explore and develop. I are also investigating the possibility that the manufacturer of the expensive infrared cameras might donate one of their demonstration models to Nova Southeastern University, which would enable us to more completely explore the use of this technology, and its potential for modification for my system. The night-shot video cameras might likewise be able to be modified to enhance their water penetrating ability and image quality. It might also be possible to adapt this technology to other applications, such as placing one on the bow of the boat, and projecting the image at the helm of the boat, so that the boat operator could, possibly, detect manatees in the water, or after dark, that they would not otherwise see. The appeal of this type of technology is that it is already familiar to most people, and thus learning to use it would not be a major burden on the operator. The cost of such a system would also probably not result in a major increase in the cost of the boat itself. Over the course of this investigation, one NSU Oceanographic Center graduate student has almost completed her thesis, and another has started on her thesis. Preliminary results of this investigation were presented at the second annual Southeast and Mid-Atlantic Marine Mammal Symposium (SEAMAMMS) held 12-14 April 2002 in Conway, SC. Ms. Paine is currently in the final stages of completing her master’s degree thesis. Paine, A.L, W.E. Baxley, and E. O. Keith. (2002). Investigating the feasibility of thermal infrared imaging technology for passive marine mammal detection. Southeast and Mid-Atlantic Marine Mammal Symposium. 12- 14 April, Conway, SC. Paine, A. (In Prep). Investigating Applications of Thermal Infrared Technology for Passive Marine Mammal Detection. M.S. Thesis. Oceanographic Center, Nova Southeastern University, Ft. Lauderdale, FL Finally, I believe that there has been a significant scientific spin-off from my investigation. The inability to detect manatee exhalations using the true infrared camera, or any of the technologies I examined, provides the first evidence that I are aware of that manatees exhale air at near ambient temperature, which as was mentioned above, has been documented in other animals as a water conservation mechanism. In their natural environment manatees almost never encounter fresh water, and thus must derive all of their water either from the food they eat (preformed water) or from metabolism. This necessitates a variety of water conservation mechanisms, such as the excretion of a highly concentrated urine, a thick water impervious skin, and a lack of thermoregulatory sweating. I have here provided evidence of yet another important adaptation that enables manatees to exist without ever needing to drink fresh or salt water

A Matrix Model of Fasting Metabolism in Northern Elephant Seal Pups

Northern elephant seal (Mirounga angustirostris) pups maintain a paradoxical fasting hyperglycemia while fasting for 6–8 weeks after nursing ~30 days. The hyperglycemia results from low rates of glucose utilization (due to low insulin) and high rates of glucose carbon recycling. Fatty acids are the major energy substrate during this time, with high rates of palmitate turnover and low ketone levels, as well as nitrogen conservation and low urea turnover. First order rate constants for the model were taken from the literature and entered into a ten compartment matrix model of metabolite flux. Eigenvalues and eigenvectors of the matrix were determined. The initial conceptualization, where carbon atoms left the model, yielded nonzero negative eigenvalues, indicating an open, stable system. Inclusion of a sink which accumulated carbon atoms yielded the same set of negative eigenvalues, and a zero eigenvalue, indicating that this system was closed and stable. The trace (β) of the matrix was a negative real number in both cases, while the determinant () of the matrix was a negative real number in the first case (no sink), and zero in the second case (sink), indicating that the system lies near a stable saddle point in the dimensionless β- phase-plane. The predicted stability of the model system is difficult to reconcile with the biological reality of a fasting animal that cannot survive forever without nutrient inputs

Using the West Indian Manatee (Trichechus manatus) as a Mechanism for Invasive Aquatic Plant Management in Florida

West-Indian manatees (Trichechus manatus L.) are opportunistic, herbivorous aquatic mammals that occupy the warm, shallow coastal waters throughout the southeastern United States. Manatees are known to feed on large quantities of diverse plant types. Presently within the state of Florida, manatees are an endangered species facing environmental and anthropogenic threats. Several different organizations work to rescue and rehabilitate these animals for an eventual return to the wild. Also within Florida, invasive aquatic plants are becoming increasingly problematic, creating both negative economic and environmental impacts. Each year, efforts are made to control these exotic plant species through several different methods. However, physical, mechanical, chemical and biological means to contain nonindigenous plants each have their drawbacks. There is a need for a natural, integrated approach to invasive aquatic plant management. The opportunity for manatees to control exotic plant species within the Florida ecosystem exists, but is improbable because of inadequate population densities. This study builds on this potential examining the use of manatees held in captivity as a tool for management by utilizing the physical collection of targeted nonindigenous plants to supplement the diet of rehabilitated manatees. Provisions are augmented with nutrients that manatees may not obtain from other sources typically found in captive diets. Early introduction of natural plants may allow for an easier transition to normal feeding patterns upon release and may condition animals to continue consumption of exotic plants in the wild. Each step has the potential to contribute to the reduction of invasive aquatic plants in Florida, and presents a cost-effective feeding alternative for manatee rehabilitation facilities. This method promotes a native Florida species as a natural solution to the problem

Using the West Indian Manatee (Trichechus manatus) as a Mechanism for Invasive Aquatic Plant Management in Florida

ABSTRACT West Indian manatees (Trichechus manatus L.) are opportunistic, herbivorous aquatic mammals that occupy the warm, shallow coastal waters throughout the southeastern United States. Manatees are known to feed on large quantities of diverse plant types. Presently within the state of Florida, manatees are an endangered species facing environmental and anthropogenic threats. Several different organizations work to rescue and rehabilitate these animals for an eventual return to the wild. Also within Florida, invasive aquatic plants are becoming increasingly problematic, creating both negative economic and environmental impacts. Each year, efforts are made to control these exotic plant species through several different methods. However, physical, mechanical, chemical and biological means to contain nonindigenous plants each have their drawbacks. There is a need for a natural, integrated approach to invasive aquatic plant management. The opportunity for manatees to control exotic plant species within the Florida ecosystem exists, but is improbable because of inadequate population densities. This study builds on this potential examining the use of manatees held in captivity as a tool for management by utilizing the physical collection of targeted nonindigenous plants to supplement the diet of rehabilitated manatees. Provisions are augmented with nutrients that manatees may not obtain from other sources typically found in captive diets. Early introduction of natural plants may allow for an easier transition to normal feeding patterns upon release and may condition animals to continue consumption of exotic plants in the wild. Each step has the potential to contribute to the reduction of invasive aquatic plants in Florida, and presents a cost-effective feeding alternative for manatee rehabilitation facilities. This method promotes a native Florida species as a natural solution to the problem

The People vs. The Florida Manatee: A Review of the Laws Protecting Florida\u27s Endangered Marine Mammal and Need for Application

Florida manatees (Trichechus manatus latirostris) are a tropical species endemic at their northernmost habitat range within the southeastern United States. Manatees face a thermoregulatory requirement during winter months and follow a seasonal migration to warm water sources. To avoid cold stress syndrome (CSS), manatees utilize the warmth from artificial sources such as power plant discharge canals or natural sources such as artesian springs. Already endangered, this species nonetheless continually faces an ever-growing threat from human impact within these important locations. This paper reviews the past and present laws protecting manatees in Florida, chronicles the impacts manatees are facing presently and in the future, and details the increasing need for the application of protection from a management standpoint. With the correct management plan in place, manatees and humans can cooperatively coexist together in a shared environment

Serologic and Hematologic Values of Bison in Colorado

Recent economic and aesthetic interest in North American bison (Bison bison) has lead to increased interstate transport of these animals. Serologic and hematologic standards for bison are needed to detect disease in transported animals as well as within herds. This paper describes variation in blood physiological parameters in bison caused by variations in diet and season. Blood was taken from six bison and analyzed for serologic and hematologic parameters. Significant variation was found in blood urea nitrogen, chloride, cholesterol, creatinine, eosinophil, glucose, hemoglobin, lactic dehydrogenase, leukocyte, packed cell volume, potassium, serum globulin, serum glutamic oxalacetic transaminase, SGPT, and sodium levels between animals receiving a high energy-high nitrogen diet and animals receiving a low energy-low nitrogen diet