Basic Husbandry: Hospitalizing the Sea Turtle

Introduction

Sea turtles, along with other turtles and tortoises, are part of order Testudines. There are seven living species of sea turtle species, including the flatback (Natator depressus), green (Chelonia mydas), hawksbill (Eretmochelys imbricata), Kemp’s ridley (Lepidochelys kempii), olive ridley (Lepidochelys olivacea), leatherback (Dermochelys coriacea),and loggerhead (Caretta caretta) (Bowen and Karl 2007) (Fig 1).

Figure 1. Sea turtle species are found in all oceans of the world except for the Arctic ocean. Photo credit: dbaist5 [CC-BY-2.0 (http://creativecommons.org/ licenses/by/2.0/] via Flickr Creative Commons. Click image to enlarge.

Dry docking the sea turtle

Ill and injured sea turtles are often initially “dry-docked” on a padded surface. Closed cell foam padding, the type used to make boat seats, can be useful in reducing the risk of pressure sores. The turtle can initially be kept moist by regular misting. If kept out of water for a prolonged period, petroleum jelly, water-based lubricants, or vitamin A & D ointment may be applied to the skin. An alternative option is to spray the turtle with temperature-controlled water (Fig 2).

Figure 2. Turtles that are too weak to go in water are dry docked (right), placed in shallow water, or on a waterbed. Shown left, waterbed with a shower system. Photo credit: Dr. Terry Norton. Click image to enlarge.

Rehabilitation tanks

Sea turtles require tanks with nonabrasive surfaces. When available, specially designed circular or oval fiberglass tanks work well. Where recirculated water is used, filtration is required, as well as continuous flow and control over water temperature and salinity. The entire life support system should be outside the tank (Fig 3) because sea turtles might destroy and ingest parts. Outdoor enclosures with direct and indirect sunlight or full-spectrum lighting with a natural photoperiod are also beneficial. Quarantine tanks for new arrivals are highly recommended.

Figure 3. A waterbed that recirculates heated water with a controlled shower can be used to support sea turtle patients that cannot be placed in water. Photo credit: Dr. Terry Norton at Mote Marine Laboratory. Click image to enlarge.

Good water quality is an essential part of housing sea turtles for rehabilitation purposes. Water is provided to sea turtles through closed, semi-open, or open systems.

• A closed system is defined here as artificial salt water that is filtered and continuously reused.
• An open or flow-through system pumps natural water from the ocean. Water passes through each tank only once before returning to its original source. Filtration or wastewater treatment may or may not be used. A turnover rate of 3 to 6 total volume replacements per 24 hours is essential.
• A semi-open system pumps water in from the ocean, but uses filtration and water recirculation or stationary water that is changed daily.

Water levels in rehabilitation tanks should be adjustable to accommodate turtles with varying degrees of debilitation (Fig 4). Like all reptiles, sea turtles are ectothermic and thus depend on external heat for all bodily functions. Water temperature should be kept warmer (26.5ºC or 80ºF) for new arrivals and the critically ill to improve immune function. In regions with colder water temperatures, slowly decrease water temperature to 23ºC (75ºF) as the turtle’s condition improves. Prior to release, acclimate the turtle to current ocean temperatures.

Figure 4. Water levels in rehabilitation tanks should be adjustable. Photo credit: Dr. Terry Norton. 

In cold stunned turtles, the water or room temperature should be just above the patient’s temperature upon arrival, approximately 3ºC (5ºF). Significant shifts in blood pH and electrolytes occur with core body temperature changes, therefore gradual changes are important to lessen physiological stress. Increase water temperature by small increments daily until the desired core body temperature is reached.

Summary

Debilitated sea turtles are often too weak to be housed in water upon presentation. Instead these patients are maintained on a padded surface or waterbed. If the period of dry docking is prolonged, the skin should be protected with the use of temperature-controlled water spray or the application of topical ointment or lubricant. Once the turtle is strong enough for transfer to a smooth-sided tank, it is imperative that good water quality is maintained.

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