The Role of Animal Rescue, Rehabilitation, and Release in Marine Conservation

The Role of Animal Rescue, Rehabilitation, and Release in Marine Conservation  

By, McKenna Longo

Introduction

Rescue, rehabilitation, and release is the process of finding a sick or injured organism taking it in for treatment, and then releasing and tracking it once treatment is completed. Recently, there has been a growing need for rescue, rehabilitation, and release practices due to the ongoing anthropogenic causes of mortality from fisheries and other human activity. 

Marine mammals such as cetaceans, sea turtles, marine bird species, and pinnipeds are some of the most affected marine organisms by anthropogenic causes of mortality. 

Anthropogenic Causes of Mortality

Anthropogenic causes of mortality are human-caused events or threats to terrestrial or marine ecosystems that have a fatal effect on wildlife. Specifically, the marine environment faces anthropogenic threats from, fisheries, sound pollution, etc. 

There is no doubt that since the industrial revolution that human civilization has had a negative impact on marine biodiversity. Overfishing, destruction of habitats, and more have taken their toll on the marine environment especially on invertebrates (Hunter, 2007). 

Overfishing is an ongoing threat to the marine animal population that is posed by fisheries. Currently, 60% of global fish stocks are fished sustainably, 34% of fish stocks are overfished, and only 6% of fish stock is underfished (Ritchie and Roser, 2021). Any more continued increase in overfishing of fish stock can lead to disruption in marine food chains. Overfishing not only affects the population ecology but typically disrupts secondary production in marine ecosystems (Coll, et al, 2008).

Photo from https://ourworldindata.org/fish-and-overfishing#methods-of-fishing

Bycatch is the incidental capture of non-target species such as cetaceans, pinniped, etc. 

Fisheries use equipment such as Purse seines, dredges, trawls, etc. to efficiently capture larger amounts of target fish species. A downside to this equipment is that the number of bycatch increases (Coll, et al, 2008). 

Larger marine animals like seals, dolphins, and sea turtles get caught or injured by these kinds of fishing equipment, which is termed ghost fishing. Also, marine animals sometimes get directly struck by fishing vessels causing injury or even death. 

                    Photo from https://www.iss-foundation.org/knowledge-tools/reports/technical-reports/download-info/non-target-species-caught-in-tuna-fisheries/

Rescue, Rehabilitation, and Release methods. 

1. Rescue

Before rescuing can occur, typically an animal must be reported. Usually, this is done by a passerby who came across the animal and contacted their local rehabilitator, or state fish and wildlife services. 

Once rescuers arrive on the scene, they must assess the situation before taking any further action. Rescue techniques vary depending on the animal, severity of the injury, and location of the situation. 

Rescuers may have an easy process of being able to capture the animal in its place or might be more complicated due to the size of the animal. 

Once the animal is stabilized and safely secured, they are transported to a rehabilitation facility.

2. Rehabilitation

Medical treatment typically is the first step in rehabilitation. Treatment can be quick and easy such as removing a net around a pinniped’s neck that will allow it to be released immediately upon treatment. 

If the situation is more complex, the animal will have to be removed from the scene and transported to a facility for treatment (Moore, et al, 2007). 

Specific treatment depends on the severity of injury and species of animal. Sometimes the injury is severe enough where time is needed for the animal to heal or must relearn an everyday ability, like eating, swimming, or flying.

3. Release

Once treatment is complete or gets to a certain point, rehabilitators will deem the animal releasable or non-releasable. 

Location determination can vary due to where the rehabilitators believe the animal will have the best chance at survival and reproducing, or a location where population abundance is low and there is a need for more reproductively mature individuals.

Post-release tracking is the process of assessing the progress of a rehabilitated animal. The goal of tracking the rehabilitated animal is to allow rehabilitators to learn from the experience. 

They can see what they did that worked well (high rates of survival) and what did not (low rates of survival). It is now encouraged to tag all released marine animals to better understand their population status. 

                Blonde seal (Phoca vitulina) found on shore with fishing net around its neck (https://www.storytrender.com/95928/blonde-seal-strangled-by-plastic-fishing-net-on-norfolk-coastline/)                                        

Concerns with rehabilitation

One of the main goals of marine animal rehabilitation is population conservation. As threats of anthropogenic causes of mortality begin to increase, population numbers of marine animals decrease. Rehabilitation efforts are not always one hundred percent effective. They do raise points of concern such as 1. Being unfit and unable to compete. 2. Bringing in outside parasites and pathogens to the population. 3. Disrupting social orders. (Lounsbury, et al., 1991).

 Being unfit and unable to compete. The goal is to make sure the animal can successfully survive and reproduce with others to aid in population conservation. Releasing an unfit animal back into the wild can result in maladaptive traits, intraspecific competition among populations near carrying capacity, etc.

Another growing concern is pathogens and parasites getting into populations from newly released marine animals. A newly rehabilitated animal can introduce a novel or modified pathogen that it picked up before or during its rehabilitation process (Moore, et al, 2007). Without checking for parasites prior, the pathogen can spread to the wild populations which could lead to a decrease in individual fitness and death rates. Parasites are a similar concern. Almost all invertebrates carry parasites, several at a time even (Evans and Raga, 2001).

Disruption in social interactions is a concern; rehabilitators must look at it before releasing a marine animal back into the wild. Many marine animals are known to have complex social orders, that can be disrupted easily. Aggressive behaviors such as being territorial, competition for food or mates, etc. can cause negative intraspecific interactions that can reduce the population's overall fitness. Rehabilitators must take in all of those factors before being able to release an animal back into the wild.

Synthesis and speculation (Conclusion)  

Anthropogenic causes of mortality have caused target populations or non-target populations marine animal populations to decline at an alarming rate and change needs to happen soon. Management of fisheries, by setting standards and rules must be worked towards to help reduce the disastrous trends that are seen with fisheries (Norse, and Crowder, 2005).

 

We must also look at responsibility intervening. Rehabilitators must consider the cost, time, population capacity, and chance the animal has before they decide to further rehabilitate. (Lounsbury, Valerie J., et al., 1991). As scientists and rehabilitators, there needs to be a less glamorized approach to rescuing, rehabilitating, and releasing sick and injured animals. The money and effort that is being put into caring for these animals should be allocated in a way that is scientifically more efficient and not glamorized for public opinion.

As we move forward, rehabilitation efforts and structure should continue to be developed and modified to increase the amount of success in rescue, rehabilitation, and release on population conservation. Additionally, the development of better methods to reduce the amount of overfishing, bycatch, and sound pollution can help take some of the stress of marine animal populations, allowing them to regenerate and get back to safe numbers.

Works cited

1.     Coll, Marta, et al. “Ecosystem Overfishing in the Ocean.” PLoS ONE, edited by Andy Hector, vol. 3, no. 12, Dec. 2008, p. e3881

2.     Evans, Peter G. H., and Juan Antonio Raga, editors. Marine Mammals: Biology and Conservation. Kluwer Academic/Plenum Publishers, 2001.

3.     Flamm, Richard O., and Karin Braunsberger. “Applying Marketing to Conservation: A Case Study on Encouraging Boater Reporting of Watercraft Collisions with Florida Manatees.” Ocean & Coastal Management, vol. 96, Aug. 2014, pp. 20–28.

4.  Lounsbury, Valerie J., et al. Rescue, Rehabilitation, and Release of Marine Mammals: An Analysis of Current Views and Practices: Proceedings of a Workshop Held in Des Plaines, Illinois, 3-5 December 1991. U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Office of Protected Resources, 1996.

5.  Moore, Michael, et al. “Rehabilitation and Release of Marine Mammals in the United States: Risks and Benefits.” Marine Mammal Science, vol. 23, no. 4, 2007, pp. 731–50.

6.  Norse, Elliott A., and Larry B. Crowder, editors. Marine Conservation Biology: The Science of Maintaining the Sea’s Biodiversi5 parts ty. Island Press, 2005.

7.  Quakenbush, Lori, et al. “Rehabilitation and Release of Marine Mammals in the United States: Concerns from Alaska.” Marine Mammal Science, vol. 25, no. 4, Oct. 2009, pp. 994–99.

8.  Ritchie, Hannah, and Max Roser. “Biodiversity.” Our World in Data, Apr. 2021. ourworldindata.org, https://ourworldindata.org/fish-and-overfishing.