**2.5 Terrestrial zone (Hatching)**

The Kemps ridley turtle uses terrestrial ecosystem during three stages of its life cycle: nesting females, eggs, and hatchlings. The principal Kemp's ridley nesting beach at Rancho Nuevo is characterised by small dunes of variable size, with vegetation that improves stability. The sand is small and fine-grained, and the beach is high energy. The nesting season runs from March to August [15]. Mass nesting events or *arribadas* occur mainly in early April through the July period. These phenomena can be triggered by meteorological conditions represented by strong winds, primarily from the north, or by a change in atmospheric pressure [17].

Kemp's ridley nesting typically occurs during the day; however, reports of sporadic cases of nocturnal nesting exist in Texas. Clutch incubation lasts between 45–60 days, and climatic conditions act directly on embryo development with incubation duration and hatchling sex ratios affected by temperature. Studies have shown that sex ratios are male-biased at the beginning of the nesting season when temperatures are lower. In contrast, nests produce mainly female hatchlings when laid during the second arribada when temperatures are highest [18].

### **2.6 Neritic zone (juvenile stage and adult stage)**

The hatchlings, after being released on the sand, immediately begin their trajectory to the ocean. The hatchlings swim using the energy provided by the nutrients found in the yolk of their egg, which lasts for a maximum of 4 days, during this period, the hatchlings migrate to ideal areas for their development. Hatchlings enter the surf and orient seaward into the waves, diving as they break, thus being swept seaward by the motion of the waves without significant energy expenditure. Like other species, the hatchlings can perceive the waves' movements to guide them towards the sea, the same mechanism they use on the way back to the coast, recognising the magnetic orientation. Juveniles reach adulthood in neritic waters, which are their most frequently used habitat. The Gulf of Mexico's northern coast is home to the majority of kemps ridley sea turtles, principally in waters no greater than 37 m deep. Although kemps ridley turtles may consume algae, their diet is primarily carnivorous and primarily based on crabs, but occasionally includes clams, shrimp, jellyfish and some fish species. Turtles may also scavenge in benthic areas on marine debris [15].

### **2.7 Oceanic zone**

The hatchlings that manage to reach oceanic or pelagic areas stop actively swimming and enter a passive state, allowing themselves to be guided by the ocean currents to foraging grounds where they remain as they develop into juveniles. Although kemps ridley sea turtles are considered a carnivorous species, individuals have been seen feeding on sargassum [15]. During their oceanic phase, juvenile turtles can be divided into two groups: the current system of the northern and western Gulf of Mexico or the Gulf Stream of the Northwest Atlantic. However, a small proportion of the population finds its way to the Mediterranean Sea. During this period that lasts between 1 to 4 years, juveniles complete their oceanic feeding phase to return to surface waters within the Gulf of Mexico and the northwest Atlantic, in US waters, where they continue to forage.

#### **3. Status**

#### **3.1 Threats**

Sea turtle populations face multiple threats which need research and monitoring to understand how these threats are detrimental to their populations and conservation. Overlooking the multiple threats that species face throughout their life cycle puts the success of recovery plans at risk [19].

#### **3.2 Illegal hunting: direct consumption and illegal trade**

Globally, fishing and eggs collection for human consumption are the principal causes of the drastic reduction in sea turtle populations, and the Kemp's ridley is no exception. In the late 1960s, excessive capture of adult kemps ridley turtles and their eggs, contributed to the drastic reduction by almost 99% of the Kemp's ridley nesting population. Turtle eggs are considered an aphrodisiac in some countries [19]. The consumption of turtle eggs is not as frequent in the United States of America and Mexico as it was before the federal government bans on harvest and consumption. However, despite governmental agencies and non-governmental organisations efforts with protection and public awareness programs, consumption continues in some coastal communities.

**121**

Mexico [24].

*Rediscovering Kemp's Ridley Sea Turtle (*Lepidochelys kempii*): Molecular Analysis and Threats*

Climate change can have a severe impact on turtle populations. All reptiles, including sea turtles, are dependent on environmental temperature, which they use to regulate their physiology [20]. Sex determination in sea turtles is directly dependent on environmental temperature. Therefore, projected anthropogenic climate change will alter the sand temperature, affecting the primary sex ratios and increas-

Sea turtles can mistake plastic objects floating in the water column for food, such as jellyfish. If ingested these inorganic materials can choke or cause obstructions in the turtle digestive systems. They can also become entangled in discarded fishing lines and nets, drowning or unable to feed or swim. Trash on beaches can

During 2010 an accident occurred on the Deepwater Horizon platform that triggered an oil spill from the platform into the Gulf of Mexico This event negatively impacted the marine ecosystem, including the kemps ridley turtle as their essential habitats and migratory routes were affected by the spill [21]. However, the extent to which this oil spill was responsible for the decrease in the Kemp's ridley population observed in the years following the disaster is unknown, with other factors possibly contributing to the decline. Continued monitoring is essential to understanding the

Every year thousands of turtles are accidentally caught by the shrimp fishery. Sea turtles must surface to breathe, so prolonged periods trapped in submerged fishing gear leads to drowning. Fisheries that use longlines and gillnets are also major causes of sea turtle mortality [22]. Although laws requiring the use of sea turtle excluder devices in shrimp fishery exist, turtles continue to become trapped

Uncontrolled coastal development has destroyed beaches that are essential for nesting. The lights coming from roads and buildings confuse hatchlings and disorienting them away from the sea. Vehicles used in beach restoration projects, including dredging and sand nourishment projects, damage near-shore foraging areas and beaches, and can also destroy nests and hatchlings. These activities referred to as "beach maintenance" have been reported on Padre Island, where machinery has prevented hatchlings from reaching the water, leaving them trapped and exposed to vehicle traffic [15].

Harmful algal blooms in the oceans are natural phenomena that occur as a result of increasing temperature, alteration of ocean currents, intensification or weakening of local nutrient upwelling, and heavy precipitation and storm events causing changes in land runoff [23]. Brevetoxins are a group of biotoxins produced mainly by algae *Karenia brevis*, which is the cause of the main harmful algal blooms (HABs) along the coast of south-west Florida, with periodic blooms throughout the Gulf of

**3.6 Coastal development: beach modification and human presence**

ing the risk of instability in the composition of sea turtle populations.

trap hatchlings and prevent them from reaching the sea.

long-term effects of this and other oil spill events.

*DOI: http://dx.doi.org/10.5772/intechopen.96655*

**3.4 Marine pollution: rubbish and oil**

**3.3 Climate change**

**3.5 Bycatch**

and drown in these nets.

**3.7 Marine biotoxins**

*Rediscovering Kemp's Ridley Sea Turtle (*Lepidochelys kempii*): Molecular Analysis and Threats DOI: http://dx.doi.org/10.5772/intechopen.96655*

## **3.3 Climate change**

*Natural History and Ecology of Mexico and Central America*

**2.6 Neritic zone (juvenile stage and adult stage)**

Atlantic, in US waters, where they continue to forage.

puts the success of recovery plans at risk [19].

continues in some coastal communities.

**3.2 Illegal hunting: direct consumption and illegal trade**

**2.7 Oceanic zone**

**3. Status**

**3.1 Threats**

The hatchlings, after being released on the sand, immediately begin their trajectory to the ocean. The hatchlings swim using the energy provided by the nutrients found in the yolk of their egg, which lasts for a maximum of 4 days, during this period, the hatchlings migrate to ideal areas for their development. Hatchlings enter the surf and orient seaward into the waves, diving as they break, thus being swept seaward by the motion of the waves without significant energy expenditure. Like other species, the hatchlings can perceive the waves' movements to guide them towards the sea, the same mechanism they use on the way back to the coast, recognising the magnetic orientation. Juveniles reach adulthood in neritic waters, which are their most frequently used habitat. The Gulf of Mexico's northern coast is home to the majority of kemps ridley sea turtles, principally in waters no greater than 37 m deep. Although kemps ridley turtles may consume algae, their diet is primarily carnivorous and primarily based on crabs, but occasionally includes clams, shrimp, jellyfish and some fish species. Turtles may also scavenge in benthic areas on marine debris [15].

The hatchlings that manage to reach oceanic or pelagic areas stop actively swimming and enter a passive state, allowing themselves to be guided by the ocean currents to foraging grounds where they remain as they develop into juveniles. Although kemps ridley sea turtles are considered a carnivorous species, individuals have been seen feeding on sargassum [15]. During their oceanic phase, juvenile turtles can be divided into two groups: the current system of the northern and western Gulf of Mexico or the Gulf Stream of the Northwest Atlantic. However, a small proportion of the population finds its way to the Mediterranean Sea. During this period that lasts between 1 to 4 years, juveniles complete their oceanic feeding phase to return to surface waters within the Gulf of Mexico and the northwest

Sea turtle populations face multiple threats which need research and monitoring to understand how these threats are detrimental to their populations and conservation. Overlooking the multiple threats that species face throughout their life cycle

Globally, fishing and eggs collection for human consumption are the principal causes of the drastic reduction in sea turtle populations, and the Kemp's ridley is no exception. In the late 1960s, excessive capture of adult kemps ridley turtles and their eggs, contributed to the drastic reduction by almost 99% of the Kemp's ridley nesting population. Turtle eggs are considered an aphrodisiac in some countries [19]. The consumption of turtle eggs is not as frequent in the United States of America and Mexico as it was before the federal government bans on harvest and consumption. However, despite governmental agencies and non-governmental organisations efforts with protection and public awareness programs, consumption

**120**

Climate change can have a severe impact on turtle populations. All reptiles, including sea turtles, are dependent on environmental temperature, which they use to regulate their physiology [20]. Sex determination in sea turtles is directly dependent on environmental temperature. Therefore, projected anthropogenic climate change will alter the sand temperature, affecting the primary sex ratios and increasing the risk of instability in the composition of sea turtle populations.

## **3.4 Marine pollution: rubbish and oil**

Sea turtles can mistake plastic objects floating in the water column for food, such as jellyfish. If ingested these inorganic materials can choke or cause obstructions in the turtle digestive systems. They can also become entangled in discarded fishing lines and nets, drowning or unable to feed or swim. Trash on beaches can trap hatchlings and prevent them from reaching the sea.

During 2010 an accident occurred on the Deepwater Horizon platform that triggered an oil spill from the platform into the Gulf of Mexico This event negatively impacted the marine ecosystem, including the kemps ridley turtle as their essential habitats and migratory routes were affected by the spill [21]. However, the extent to which this oil spill was responsible for the decrease in the Kemp's ridley population observed in the years following the disaster is unknown, with other factors possibly contributing to the decline. Continued monitoring is essential to understanding the long-term effects of this and other oil spill events.

## **3.5 Bycatch**

Every year thousands of turtles are accidentally caught by the shrimp fishery. Sea turtles must surface to breathe, so prolonged periods trapped in submerged fishing gear leads to drowning. Fisheries that use longlines and gillnets are also major causes of sea turtle mortality [22]. Although laws requiring the use of sea turtle excluder devices in shrimp fishery exist, turtles continue to become trapped and drown in these nets.

### **3.6 Coastal development: beach modification and human presence**

Uncontrolled coastal development has destroyed beaches that are essential for nesting. The lights coming from roads and buildings confuse hatchlings and disorienting them away from the sea. Vehicles used in beach restoration projects, including dredging and sand nourishment projects, damage near-shore foraging areas and beaches, and can also destroy nests and hatchlings. These activities referred to as "beach maintenance" have been reported on Padre Island, where machinery has prevented hatchlings from reaching the water, leaving them trapped and exposed to vehicle traffic [15].

#### **3.7 Marine biotoxins**

Harmful algal blooms in the oceans are natural phenomena that occur as a result of increasing temperature, alteration of ocean currents, intensification or weakening of local nutrient upwelling, and heavy precipitation and storm events causing changes in land runoff [23]. Brevetoxins are a group of biotoxins produced mainly by algae *Karenia brevis*, which is the cause of the main harmful algal blooms (HABs) along the coast of south-west Florida, with periodic blooms throughout the Gulf of Mexico [24].

Sea turtles are affected by marine biotoxins present in the water column, in aerosols generated by waves, or through the consumption of contaminated prey [25]. In recent years, the impacts of these phenomena have caused or contributed to sea turtle mass mortality events in *C. mydas*, *C. caretta*, *L. olivacea* and *L. kempii* [26].

## **4. Studies**

#### **4.1 Satellite telemetry**

Studies that follow in water movements of sea turtles and other marine vertebrates often use tagging to shed light on migration routes and local movements. The most common ways to tag sea turtles are to apply external metallic tags with unique codes usually to the turtle flippers which allow the individual turtle to be identified. This method requires the turtle to be recaptured and does not supply information on the routes taken from release and capture position. The advent of satellite telemetry in the 90s and improving technology has allowed researchers to follow the routes taken by sea turtles and better understand habitat use and connectivity [27].

Satellite tagging of Kemp's ridley sea turtles, as with other sea turtle species requires the attachment of platform terminal transmitters PTT to the turtle's carapace using epoxy glue. The study of the migration of kemps ridley turtles began in 1995 and has focused mainly on post-nesting females. These marked females confirmed that Kemp's ridley turtles keep mainly to the Gulf of Mexico, and forage near the North Texas and Louisiana coasts in the USA. Satellite tracking of juvenile turtles shows that they live off the coast of Veracruz and that they nest mainly in Tamaulipas and more specifically in Rancho Nuevo Sanctuary. Additionally, information on foraging site fidelity is easily obtained from satellite telemetry studies. Furthermore, studies have also indicated that male Kemp's ridley turtles typically remain off the coast of Tamaulipas, close to the principal nesting area [28].

Satellite telemetry has also shed light on nesting and nest-site fidelity. Tracked females have been shown to nest one to three times at the same site. Additionally, the distance females migrate from nesting sites to the open ocean decreased as the number of times they returned to nest increased. Somewhat surprisingly satellite telemetry has shown that turtles do not forage during the inter-nesting period, and they minimise energy loss by spending most of their time resting, limiting movement.

Of the studies on female kemps ridley movements between nesting events, information is only available for three individuals. These studies found that after nesting one tagged female travelled north [29] from the main nesting site at Rancho Nuevo Sanctuary; two turtles have travelled south from Rancho Nuevo with one covering a distance of ~100 km Further studies are required to understand Kemps ridley movements between nesting events.

#### **4.2 Biochemical studies**

Sea turtles play an important role in ocean ecosystems, by maintaining healthy seagrass beds, beaches, estuaries, and reefs. In turn, they are considered sentinel species for ecosystem health, since their longevity and physiology provide essential and early information on marine and coastal habitats and the local environments in which they live, which provides a quick risk diagnosis. These reptiles are particularly susceptible to pathogens such as parasites, bacteria, fungi and viruses. Examples of these parasites are for bacteria: *Vibrio* spp. *Pseudomonas* spp., *Enterococcus* spp., *Aeromonas*, *Cytophaga*, and others; for fungi: *Fusarium*

**123**

*Rediscovering Kemp's Ridley Sea Turtle (*Lepidochelys kempii*): Molecular Analysis and Threats*

species *Fusarium solani*, *Fusarium oxysporum*, F*. solani*, and *Pseudallescheria boydii Fusarium keratoplasticum*; and viruses manly *Herpesviridae* [29]. In turn, they risk spreading diseases when in contact with other species or populations. Sea turtles are also susceptible to the toxicity and bioaccumulation of environmental pollutants that can affect their health, causing a deterioration in their immune system, and increasing the risk of them developing diseases due to the exposure to

Therefore, as part of sea turtle protection activities, incorporating a population health assessment program and identifying diseases and abnormalities in wildlife organisms is a priority. However, the lack of knowledge about the physiology of these reptiles makes it difficult to establish criteria to measure the health of their populations and to be able to distinguish between "normal" physiology and the

Multiple techniques exist to diagnose organism health, including the analysis pollutant concentrations, physical evaluation and disease detection. However, haematological methods are the most widely used as indicators of sea turtle health, since they provide information on immune, cellular and humoral factors, which are necessary for the response to adverse factors, through the blood which can indicate pathological changes in the organisms. Therefore, blood parameters are a noninvasive diagnostic tool that can be used to evaluate and monitor the health status

The evaluation of blood parameters, generally accompanied by a detailed clinical history, clinical signs, physical examination and other diagnostic tests, is an important tool for the evaluation of the health of a population through the establishment of blood reference intervals (BRI) and has made it possible to determine and evaluate the functioning of organs and confirm possible diseases in progress. However, in the case of sea turtles, there is difficulty in defining the blood reference values considered normal parameters due to the variability between sea turtles' geographic areas, ecological habitat, populations, sexual maturity, reproductive status, diet and migration. For this reason, therefore, blood parameters must be

Previous studies on the establishment of blood biochemistry reference values in other sea turtle species have found that the values are influenced by ecological implications, the season of the year and the reproductive stage. For example, adult turtles that feed in neritic habitats had low levels of creatinine (Cr), alkaline phosphatase (ALP), Phosphorus (P), Sodium (Na), Magnesium (Mg), unlike adult

By sex, significant differences have been observed in blood parameters in total protein (PT), albumin (ALB), Calcium (Ca), cholesterol (CHOL), triglycerides (TRIG), cell pack volume (PVC) and total bilirubin (TBIL) being higher in females due to its association with vitellogenesis and folliculogenesis, on the other hand, in males the levels of BUN (blood urea nitrogen) and glucose (GLU) are higher since they are associated with the lack of food during mating. In foraging areas, no significant relationship has been found between the cell packet volume (PCV) with respect to the size and sex of sea turtles, rather PVC is related to feeding and stress on the body. Other parameters such as glucose (GLU) may present higher levels in juveniles than adults, particularly in adult females since they require more energy

Finally, a significant difference has been observed in visibly sick sea turtles compared to healthy individuals, for example in turtles with fibropapillomatosis, the values of total protein (PT), albumin (ALB), cholesterol (CHOL) and triglycerides (TRIG) are lower due to the chronicity and severity of this disease, while in turtles with necrotic or traumatic lesions lower values of total protein (PT), albumin

*DOI: http://dx.doi.org/10.5772/intechopen.96655*

pollutants [30, 31].

of wildlife [33].

presence of pathologies [30, 32].

established for each species and region [31, 33].

turtles that feed in ocean habitats [34].

for the nesting process [35].

*Rediscovering Kemp's Ridley Sea Turtle (*Lepidochelys kempii*): Molecular Analysis and Threats DOI: http://dx.doi.org/10.5772/intechopen.96655*

species *Fusarium solani*, *Fusarium oxysporum*, F*. solani*, and *Pseudallescheria boydii Fusarium keratoplasticum*; and viruses manly *Herpesviridae* [29]. In turn, they risk spreading diseases when in contact with other species or populations. Sea turtles are also susceptible to the toxicity and bioaccumulation of environmental pollutants that can affect their health, causing a deterioration in their immune system, and increasing the risk of them developing diseases due to the exposure to pollutants [30, 31].

Therefore, as part of sea turtle protection activities, incorporating a population health assessment program and identifying diseases and abnormalities in wildlife organisms is a priority. However, the lack of knowledge about the physiology of these reptiles makes it difficult to establish criteria to measure the health of their populations and to be able to distinguish between "normal" physiology and the presence of pathologies [30, 32].

Multiple techniques exist to diagnose organism health, including the analysis pollutant concentrations, physical evaluation and disease detection. However, haematological methods are the most widely used as indicators of sea turtle health, since they provide information on immune, cellular and humoral factors, which are necessary for the response to adverse factors, through the blood which can indicate pathological changes in the organisms. Therefore, blood parameters are a noninvasive diagnostic tool that can be used to evaluate and monitor the health status of wildlife [33].

The evaluation of blood parameters, generally accompanied by a detailed clinical history, clinical signs, physical examination and other diagnostic tests, is an important tool for the evaluation of the health of a population through the establishment of blood reference intervals (BRI) and has made it possible to determine and evaluate the functioning of organs and confirm possible diseases in progress. However, in the case of sea turtles, there is difficulty in defining the blood reference values considered normal parameters due to the variability between sea turtles' geographic areas, ecological habitat, populations, sexual maturity, reproductive status, diet and migration. For this reason, therefore, blood parameters must be established for each species and region [31, 33].

Previous studies on the establishment of blood biochemistry reference values in other sea turtle species have found that the values are influenced by ecological implications, the season of the year and the reproductive stage. For example, adult turtles that feed in neritic habitats had low levels of creatinine (Cr), alkaline phosphatase (ALP), Phosphorus (P), Sodium (Na), Magnesium (Mg), unlike adult turtles that feed in ocean habitats [34].

By sex, significant differences have been observed in blood parameters in total protein (PT), albumin (ALB), Calcium (Ca), cholesterol (CHOL), triglycerides (TRIG), cell pack volume (PVC) and total bilirubin (TBIL) being higher in females due to its association with vitellogenesis and folliculogenesis, on the other hand, in males the levels of BUN (blood urea nitrogen) and glucose (GLU) are higher since they are associated with the lack of food during mating. In foraging areas, no significant relationship has been found between the cell packet volume (PCV) with respect to the size and sex of sea turtles, rather PVC is related to feeding and stress on the body. Other parameters such as glucose (GLU) may present higher levels in juveniles than adults, particularly in adult females since they require more energy for the nesting process [35].

Finally, a significant difference has been observed in visibly sick sea turtles compared to healthy individuals, for example in turtles with fibropapillomatosis, the values of total protein (PT), albumin (ALB), cholesterol (CHOL) and triglycerides (TRIG) are lower due to the chronicity and severity of this disease, while in turtles with necrotic or traumatic lesions lower values of total protein (PT), albumin

*Natural History and Ecology of Mexico and Central America*

**4. Studies**

**4.1 Satellite telemetry**

Sea turtles are affected by marine biotoxins present in the water column, in aerosols generated by waves, or through the consumption of contaminated prey [25]. In recent years, the impacts of these phenomena have caused or contributed to sea turtle mass mortality events in *C. mydas*, *C. caretta*, *L. olivacea* and *L. kempii* [26].

Studies that follow in water movements of sea turtles and other marine vertebrates often use tagging to shed light on migration routes and local movements. The most common ways to tag sea turtles are to apply external metallic tags with unique codes usually to the turtle flippers which allow the individual turtle to be identified. This method requires the turtle to be recaptured and does not supply information on the routes taken from release and capture position. The advent of satellite telemetry in the 90s and improving technology has allowed researchers to follow the routes taken by sea turtles and better understand habitat use and connectivity [27]. Satellite tagging of Kemp's ridley sea turtles, as with other sea turtle species requires the attachment of platform terminal transmitters PTT to the turtle's carapace using epoxy glue. The study of the migration of kemps ridley turtles began in 1995 and has focused mainly on post-nesting females. These marked females confirmed that Kemp's ridley turtles keep mainly to the Gulf of Mexico, and forage near the North Texas and Louisiana coasts in the USA. Satellite tracking of juvenile turtles shows that they live off the coast of Veracruz and that they nest mainly in Tamaulipas and more specifically in Rancho Nuevo Sanctuary. Additionally, information on foraging site fidelity is easily obtained from satellite telemetry studies. Furthermore, studies have also indicated that male Kemp's ridley turtles typically remain off the coast of Tamaulipas, close to the principal nesting area [28].

Satellite telemetry has also shed light on nesting and nest-site fidelity. Tracked females have been shown to nest one to three times at the same site. Additionally, the distance females migrate from nesting sites to the open ocean decreased as the number of times they returned to nest increased. Somewhat surprisingly satellite telemetry has shown that turtles do not forage during the inter-nesting period, and they minimise energy loss by spending most of their time resting, limiting

Of the studies on female kemps ridley movements between nesting events, information is only available for three individuals. These studies found that after nesting one tagged female travelled north [29] from the main nesting site at Rancho Nuevo Sanctuary; two turtles have travelled south from Rancho Nuevo with one covering a distance of ~100 km Further studies are required to understand Kemps

Sea turtles play an important role in ocean ecosystems, by maintaining healthy seagrass beds, beaches, estuaries, and reefs. In turn, they are considered sentinel species for ecosystem health, since their longevity and physiology provide essential

and early information on marine and coastal habitats and the local environments in which they live, which provides a quick risk diagnosis. These reptiles are particularly susceptible to pathogens such as parasites, bacteria, fungi and viruses. Examples of these parasites are for bacteria: *Vibrio* spp. *Pseudomonas* spp., *Enterococcus* spp., *Aeromonas*, *Cytophaga*, and others; for fungi: *Fusarium*

**122**

movement.

ridley movements between nesting events.

**4.2 Biochemical studies**

(ALB), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) have been reported [36].

Some studies on sea turtle blood biochemistry from the northern Gulf of Mexico have included samples from *L. kempii* turtles, which, although the principal objective of these studies was not to establish blood reference intervals (**Table 2**), the results obtained contribute knowledge on the possible differences that the species may present by age or sex, and that factors such as diet do not influence the preprandial and postprandial hematological and plasma parameters in *L. kempii*, unlike other species of sea turtles such as *C. mydas*, in which the biochemical levels of total protein (PT), albumin (ALB), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and postprandial cholesterol (CHOL) increased significantly. The authors mention that this is due to the type of diet of each species, since juvenile *L. kempii* turtles are carnivorous and consume mainly crabs, while juvenile *C. mydas* turtles change their diet from carnivorous to herbivorous when mature [37].


*PVC = Packed cell volume, BUN = Blood urea nitrogen, ALKP = Alkaline phosphatase, ALT = Alanine aminotransferase, AST = Aspartate aminotransferase, GGT = Gamma-glutamyl transpeptidase, CK = Creatine phosphokinase, NA = Not analysed.*

#### **Table 2.**

*Reference values of blood biochemistry for different populations of clinically healthy Lepidochelys kempii sea turtles [12, 38, 39].*

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*Rediscovering Kemp's Ridley Sea Turtle (*Lepidochelys kempii*): Molecular Analysis and Threats*

The impact of gillnets on the sea turtle health, where a significant increase in enzymes such as lactate dehydrogenase (LDH) and creatinine kinase (CK), Phosphorus (P), calcium (K) and glucose (GLU) was observed the longer a turtle was trapped in the net. The authors concluded that the level of stress to which the organism is subjected to alters the blood parameters values. On the other hand, kemps ridley turtles are exposed to pollutants such as metals and organochlorine pesticides from an early age, and even low concentrations of these pollutants are associated with changes in biochemical parameters, which affects the health and

Although the *L. kempii* turtle is considered one of the sea turtle species at the greatest risk of extinction, blood biochemistry reference values have not been established. Therefore, blood biochemistry studies should be prioritised for this species as understanding the health status and disease patterns for these turtles will

Globally, ocean pollution is a high-impact problem, which is generated from multiple sources and anthropogenic activities, such as fisheries, urban development, mining, production of agricultural and industrial products and oil refineries. These activities significantly increase pollutant levels in marine ecosystems and negatively impact the health of the organisms that inhabit them. Among the primary pollutants found in marine ecosystems are organochlorine compounds, solid waste, plastics (micro and macro), pharmaceuticals, hydrocarbons and heavy metals. Heavy metals are of great importance in ecotoxicology, due to their high toxicity and duration in the environment, since bacteria cannot degrade them over

Although some metals are essential for organisms' biochemical processes (Cu, Mn, Mg, Se, Cr, As, Na, K and Mo), high levels of these elements can affect organism health. On the other hand, toxic metals (Hg, Pb and Cd) are elements that are unnecessary in organisms and can alter metabolic pathways and develop diseases and even death [35, 42, 44]. Heavy metals are acquired mainly through diet, and bioaccumulate in specific organs or tissues, such as Cd in the kidney and Pb in bones, by affinity. Through biomagnification processes heavy metals can affect the entire trophic web, with the greatest impact observed in the "top" organisms, such as sea turtles, altering blood biochemistry and other health parameters, since they have the ability to act as endocrine disruptors and produce carcinogenic effects, as

On the other hand, high concentrations of heavy metals such as Cu, Fe and Pb have been related to the presence of fibropapillomas, a disease which seriously threatens sea turtle health. For this reason, heavy metals such as Cd, Hg and Pb are the pollutants with the greatest impact on these reptiles, even affecting the embryos during vitellogenesis due to the vertical transmission from the female to her eggs; for example, Pb mimics as Ca as its reserves are depleted during nesting seasons and can be transferred to eggs. For these reasons, heavy metals have been identified as a

Although the issue of heavy metals in sea turtles has been widely studied, most studies are based on the analysis of tissues collected from dead individuals. However, this does not increase our understanding on the bioavailability, bioaccumulation and toxicology of heavy metals in sea turtles or their immune response to these pollutants, which is why blood is currently used as analysis tissue, which reflects exposure to short-term pollutants, although it has been observed that there is a relationship between metal levels in the blood with respect to that in other

*DOI: http://dx.doi.org/10.5772/intechopen.96655*

behaviour of these organisms [38].

help secure their future.

**4.3 Heavy metal studies**

short periods [40–42].

well as affecting the fertility of eggs [33, 34, 41].

risk to the health of sea turtle populations worldwide.

*Rediscovering Kemp's Ridley Sea Turtle (*Lepidochelys kempii*): Molecular Analysis and Threats DOI: http://dx.doi.org/10.5772/intechopen.96655*

The impact of gillnets on the sea turtle health, where a significant increase in enzymes such as lactate dehydrogenase (LDH) and creatinine kinase (CK), Phosphorus (P), calcium (K) and glucose (GLU) was observed the longer a turtle was trapped in the net. The authors concluded that the level of stress to which the organism is subjected to alters the blood parameters values. On the other hand, kemps ridley turtles are exposed to pollutants such as metals and organochlorine pesticides from an early age, and even low concentrations of these pollutants are associated with changes in biochemical parameters, which affects the health and behaviour of these organisms [38].

Although the *L. kempii* turtle is considered one of the sea turtle species at the greatest risk of extinction, blood biochemistry reference values have not been established. Therefore, blood biochemistry studies should be prioritised for this species as understanding the health status and disease patterns for these turtles will help secure their future.

#### **4.3 Heavy metal studies**

*Natural History and Ecology of Mexico and Central America*

been reported [36].

(ALB), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) have

change their diet from carnivorous to herbivorous when mature [37].

**Juveniles Foraging area [12]**

Sample size (n) 26 10 4 VPC NA NA NA Total protein (gdL-1) 2.6 ± 0.4 −2.4 − 17.6 2.6 ± 0.9 Albumin (gdL-1) 1.0 ± 0.2 −7.11 − 7.7 0.9 ± 0.3 Globulin (gdL-1) 1.7 ± 0.3 −7.7 − 23.8 1.7 ± 0.6 A/G ratio 0.6 ± 0.1 NA NA Total Bilirubin (mgdL-1) NA NA NA Creatinine (mgdL-1) 0.25 ± 0.11 −33.3 − 50.0 NA BUN (mgdL-1) 33 ± 22 NA 68.3 ± 20.7 Glucose (mgdL-1) 141 ± 50 −13.1 − 16.9 112.3 ± 48.8 Cholesterol (mgdL-1) 334 ± 141 −2.6 − 10.0 NA Triglycerides (mgdL-1) NA −11.8 − 25.1 NA

ALKP (UL-1) 285 ± 417 −9.9 − 12.9 NA ALT (UL-1) 26 ± 50 −100 − 50 NA AST (UL-1) 610 ± 50 −3.9 − 14.4 108.8 ± 54.9 GGT (UL-1) 3 ± 2 NA NA CK (UL-1) 21,979 ± 24,298 −2.4 − 15.8 2,412.3 ± 2,235.4 AMYL (UL-1) NA NA

Calcium (mgdL-1) 6.6 ± 1.1 −11.5 − 4.5 13.5 ± 9.7 Phosphorus (mgdL-1) 7.4 ± 1.2 −1.1 − 6.9 7.5 ± 4.0

*Reference values of blood biochemistry for different populations of clinically healthy Lepidochelys kempii sea* 

*PVC = Packed cell volume, BUN = Blood urea nitrogen, ALKP = Alkaline phosphatase, ALT = Alanine aminotransferase, AST = Aspartate aminotransferase, GGT = Gamma-glutamyl transpeptidase, CK = Creatine* 

**North Carolina Juveniles Foraging area [38]** **North Carolina Adults Foraging area [39]**

**Parameter Massachusetts**

Some studies on sea turtle blood biochemistry from the northern Gulf of Mexico have included samples from *L. kempii* turtles, which, although the principal objective of these studies was not to establish blood reference intervals (**Table 2**), the results obtained contribute knowledge on the possible differences that the species may present by age or sex, and that factors such as diet do not influence the preprandial and postprandial hematological and plasma parameters in *L. kempii*, unlike other species of sea turtles such as *C. mydas*, in which the biochemical levels of total protein (PT), albumin (ALB), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and postprandial cholesterol (CHOL) increased significantly. The authors mention that this is due to the type of diet of each species, since juvenile *L. kempii* turtles are carnivorous and consume mainly crabs, while juvenile *C. mydas* turtles

**124**

**Table 2.**

*turtles [12, 38, 39].*

Enzymes

Elements

*phosphokinase, NA = Not analysed.*

Globally, ocean pollution is a high-impact problem, which is generated from multiple sources and anthropogenic activities, such as fisheries, urban development, mining, production of agricultural and industrial products and oil refineries. These activities significantly increase pollutant levels in marine ecosystems and negatively impact the health of the organisms that inhabit them. Among the primary pollutants found in marine ecosystems are organochlorine compounds, solid waste, plastics (micro and macro), pharmaceuticals, hydrocarbons and heavy metals. Heavy metals are of great importance in ecotoxicology, due to their high toxicity and duration in the environment, since bacteria cannot degrade them over short periods [40–42].

Although some metals are essential for organisms' biochemical processes (Cu, Mn, Mg, Se, Cr, As, Na, K and Mo), high levels of these elements can affect organism health. On the other hand, toxic metals (Hg, Pb and Cd) are elements that are unnecessary in organisms and can alter metabolic pathways and develop diseases and even death [35, 42, 44]. Heavy metals are acquired mainly through diet, and bioaccumulate in specific organs or tissues, such as Cd in the kidney and Pb in bones, by affinity. Through biomagnification processes heavy metals can affect the entire trophic web, with the greatest impact observed in the "top" organisms, such as sea turtles, altering blood biochemistry and other health parameters, since they have the ability to act as endocrine disruptors and produce carcinogenic effects, as well as affecting the fertility of eggs [33, 34, 41].

On the other hand, high concentrations of heavy metals such as Cu, Fe and Pb have been related to the presence of fibropapillomas, a disease which seriously threatens sea turtle health. For this reason, heavy metals such as Cd, Hg and Pb are the pollutants with the greatest impact on these reptiles, even affecting the embryos during vitellogenesis due to the vertical transmission from the female to her eggs; for example, Pb mimics as Ca as its reserves are depleted during nesting seasons and can be transferred to eggs. For these reasons, heavy metals have been identified as a risk to the health of sea turtle populations worldwide.

Although the issue of heavy metals in sea turtles has been widely studied, most studies are based on the analysis of tissues collected from dead individuals. However, this does not increase our understanding on the bioavailability, bioaccumulation and toxicology of heavy metals in sea turtles or their immune response to these pollutants, which is why blood is currently used as analysis tissue, which reflects exposure to short-term pollutants, although it has been observed that there is a relationship between metal levels in the blood with respect to that in other


