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Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico (2017)

Chapter: Sea Turtle Restoration Monitoring

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Suggested Citation:"Sea Turtle Restoration Monitoring." National Academies of Sciences, Engineering, and Medicine. 2017. Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico. Washington, DC: The National Academies Press. doi: 10.17226/23476.
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Sea Turtle Restoration Monitoring

WHY RESTORE SEA TURTLES?

Sea turtles play numerous roles in marine ecosystems from mainland beaches to oceanic waters; for example their shells serve as mobile habitat or resting space for hundreds of species of invertebrates, fish, and birds, and they transport nutrients across ecosystems including from sea to land. As part of marine food chains, sea turtles affect many plants, animals, and habitat directly and indirectly through their foraging behavior, and as critical prey items for predators at multiple trophic levels (Heithaus, 2013). Sea turtles also play an important socioeconomic role in the Gulf of Mexico. Ecotourism centered around sea turtle nesting beach programs where the public can watch a female lay her eggs on the beach is an important part of the economies of some coastal communities. Public hatchling releases also attract thousands of tourists every year and contribute to the economies of the areas where they are held annually. International case studies have estimated gross revenue for non-consumptive use of marine turtles to average over a million U.S. dollars per site annually, and passive use value expenditures of $20 million per year on global marine turtle conservation (Troëng and Drews, 2004). However, in the Gulf the aesthetic and intrinsic nonuse values of sea turtles are unquantified.

All five species of sea turtle in the Gulf of Mexico (Kemp’s ridley, loggerhead, green, hawksbill, and leatherback) are threatened or endangered, and are protected by the U.S. Endangered Species Act (ESA, 16 U.S.C. § 1531 et seq.). For example, the Kemp’s ridley sea turtle (Lepidochelys kempii), which only nests on Gulf of Mexico beaches, declined in the 1960s-1970s after decades of egg harvest and incidental capture in fisheries. By the mid-1980s only a few hundred female Kemp’s ridleys came ashore to lay eggs in Mexico. Conservation practices implemented to reduce mortality and increase recruitment saved the species from extinction and led to exponential growth in the number of adult female Kemp’s ridleys from only a couple of hundred turtles in 1985 to nearly 10,000 turtles in 2009. The dynamics of the genetically distinct Gulf loggerhead turtle are also important to understand for restoration and monitoring purposes, as well as the Florida green turtle population, which is recovering well enough from near-extinction to be moved from endangered to threatened status in 2016.

RESTORATION OBJECTIVES

The overarching goal of sea turtle restoration in the Gulf of Mexico following the Deepwater Horizon oil spill is to implement an integrated portfolio of restoration approaches to address all injured life stages (hatchling, juvenile, and adult) and all sea turtle species, as well as to restore the food sources and habitats that turtles require (DWH NRDA Trustees, 2016). This restoration portfolio currently includes reducing mortality of sea turtles by decreasing the primary threats in marine and terrestrial environments. These threats include incidental capture in commercial and recreational fisheries, acute environmental changes (when induced by human activity), loss or degradation of nesting beach habitat (e.g., beach armoring), and other natural and anthropogenic threats. Restoration approaches also include increasing recruitment of hatchling sea turtles by expanding efforts to locate and protect sea turtle nests on beaches to reduce the primary threats to nests, eggs, and hatchlings (e.g., predators, tidal inundation, artificial lighting) (DWH NRDA Trustees, 2016). The National Oceanic and Atmospheric Administration (NOAA) Fisheries Service and the U.S. Fish and Wildlife Service (FWS) have shared jurisdiction for recovery and conservation of sea turtles listed under the ESA. NOAA leads the conservation and recovery of sea turtles in the marine environment, and FWS leads the conservation and recovery of sea turtles on nesting beaches.

Examples of common restoration objectives are provided in Table II.5, including enhancing hatching success by constructing corrals on sea turtle nesting beaches, reducing hatchling disorientation by controlling artificial lights on nesting beaches, enhancing survival by controlling predators on nesting beaches, restoring stranded turtles, and reducing adult mortality from fisheries bycatch. Most life history models indicate that population gains realized by improving conditions according to the first four objectives are often linked to reducing fishery bycatch. Table II.5 also lists a set of metrics (described below) that may help assess progress towards these objectives in many cases, and

Suggested Citation:"Sea Turtle Restoration Monitoring." National Academies of Sciences, Engineering, and Medicine. 2017. Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico. Washington, DC: The National Academies Press. doi: 10.17226/23476.
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depending on the relevant monitoring purpose (note that example metrics to support monitoring for adaptive management are not included because of their inherent project/program-specificity).

DECISION-CRITICAL UNCERTAINTIES

Sea turtles are long-lived vertebrates that have delayed maturity, complex life cycles that span multiple habitats from mainland beaches to oceanic waters, and wide-ranging migrations. Interspecific and intraspecific variation exist in the ecology and life histories of the five sea turtle species that occur in the Gulf of Mexico, however general patterns exist and these form the basis of our understanding of sea turtle distribution. Post-hatchling sea turtles are epipelagic, migrate far from land, and gather in surface circulation features such as convergence zones where seagrass, algae, and other material gather, providing food and shelter for this critical juvenile life stage. After a few years, juvenile turtles of most species migrate back towards inshore and nearshore habitats where they feed primarily on benthic organisms. Juveniles mature sexually after many years (decades for some species) and migrate to breeding areas, often located in nearshore waters adjacent to the nesting beach of their natal origin, to mate and later nest. After the breeding season adult males and females migrate to feeding areas where they may reside until their next reproductive cycle (2-5 years). Sea turtles typically disperse widely after nesting and undertake long migrations nearshore for some species and far offshore for others, crossing through the waters and territories of multiple states and nations.

A conceptual model of sea turtle life history is useful to understand the complexities of monitoring sea turtles. This qualitative model (Figure II.5), highlighted in a recent National Research Council (NRC) study undertaken to improve assessment of sea turtle status and trends (NRC, 2010), is a causal loop diagram of the Pacific loggerhead sea turtle (Caretta caretta). This model is a simple illustration of a typical sea turtle life cycle that characterizes the relationship between sea turtle demography and some of the known anthropogenic and natural stressors in a complex biological system. Coupling this conceptual model with the established practices widely used to assess sea turtle status and trends reveals deficiencies of current assessment methods. Furthermore, monitoring vital rates, such as the example metrics listed in Table II.5, can improve the capacity of models to assess sea turtle population recovery. Improving the quality and quantity of information gathered from mark-recapture and stranded animal tissue analysis should help make this link possible, and facilitate assessment of future catastrophic event impacts on vulnerable populations. Also, critical habitats for sea turtle life stages, including rafts of algae (Sargassum spp.), seagrass beds, and nearshore continental shelf habitats, have been identified but not yet well mapped.

Much of the good practice that is presented here on assessment of sea turtle status and trends is provided in greater depth in the recent NRC (2010) report; readers are advised to use this resource for details and comprehensive source information beyond the following overview. Examples of techniques discussed in this report include mark-recapture studies to estimate frequency of reproduction, annual survival, and growth of turtles on beaches and in water. Current approaches to assess sea turtle status and trends rely heavily on data collected from long-term monitoring projects that estimate the abundance of adult females nesting at beaches (NRC, 2010; Bjorndal et al., 2011). These data alone are insufficient for a number of reasons. First, using abundance data based on a single life-stage is not representative of the entire population. Data collected at nesting beaches provides estimates of only reproductively active adult females, a small fragment of any sea turtle population. Juveniles, subadults, males and non-breeding adult females are excluded from abundance estimates, therefore, we know very little about both abundance and mortality rates of these life stages. Second, because sea turtles take a long time to attain sexual maturity (decades for some species) and most adult females do not reproduce annually, decades of monitoring are needed to observe population changes and it does not enable diagnosis of the cause(s) of population increase or decrease. Finally, most fundamental vital rates necessary for population assessments cannot be collected at nesting beaches. Demographic information such as age-specific and sex-specific survival, age at sexual maturity, and other vital rates are necessary to interpret population changes, identify threats in marine habitats and their relative impacts, predict risk, evaluate the impacts of management activities, and competently assess sea turtle populations (Heppell et al., 2003; Bjorndal et al., 2011). Therefore, many key uncertainties remain regarding the above conceptual model, including abundance of various life stages in the water, reproductive and early survival rates, demographic information across the Gulf, and

Suggested Citation:"Sea Turtle Restoration Monitoring." National Academies of Sciences, Engineering, and Medicine. 2017. Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico. Washington, DC: The National Academies Press. doi: 10.17226/23476.
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Image
FIGURE II.5 A conceptual model to illustrate age-class structure and demographic processes of the Pacific loggerhead sea turtle. Plus signs indicate two components moving in the same direction; minus signs indicate components moving in opposite directions. SOURCE: NRC, 2010.

confidence in existing quantitative assessment of threats (NRC, 2010).

DEVELOP A PROJECT-LEVEL MONITORING AND ASSESSMENT PLAN

Information Needs based on Monitoring Purpose and Project Objectives

Sea turtles are difficult to monitor, and practices used to assess status and trends have focused on the life stages that are most easily accessible on land. As defined in Part I of this report, the three primary purposes of restoration monitoring include (1) assuring projects are built and are initially functioning as designed (construction monitoring); (2) assessing whether restoration goals and objectives have been or are being met (performance monitoring); and (3) informing restoration management, improving design of future restoration efforts, and increasing ecosystem understanding (monitoring for adaptive management). For these purposes, baseline monitoring of sea turtles occurs worldwide at nesting beaches using established methods that yield important information about increasing and decreasing trends of populations and species (Eckert et al., 1999). The data collected have been used extensively for many years by state and federal agencies responsible for sea turtle recovery to assess the status and trends of sea turtle populations and species, and the success of various management strategies. There are many different types of sea turtle restoration projects currently planned. These range from projects designed to protect eggs at nesting beaches to projects that will facilitate rapid response to episodic mass stranding events (see Table 4.1 and NRC [2010] for more details on the value of monitoring strandings). The types of monitoring and evaluation plans used to assess the impacts of individual projects will vary according to their objectives. As post-DWH restoration activities increasingly (but often independently) occur across the Gulf of Mexico to improve turtle-dependent habitats and food sources, it would be beneficial to coordinate such efforts (see Table 4.1 for examples of related restoration activities) to improve the likelihood of effective sea turtle recovery. Table II.5 describes the relationship between objectives of restoration projects and the metrics that are monitored to assess progress towards those objectives.

Suggested Citation:"Sea Turtle Restoration Monitoring." National Academies of Sciences, Engineering, and Medicine. 2017. Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico. Washington, DC: The National Academies Press. doi: 10.17226/23476.
×

Table II.5 Metrics Considered Good Practice to Monitor Sea Turtle Restoration Activities for Construction, Performance Toward Project Objectives, and Program-Level or Large-Scale Assessments

Monitoring Purpose
Construction Performance Program-level
Potential Monitoring Metrics Examples Examples Suggested
Habitat

Nesting beach location

#1, #2, #3 #1, #2, #3 X

Beaches where stranding data are recorded

#4 #4 X

Feeding ground location

#5 #5 X

Migratory corridor location

#5 #5 X

Date and location of possibly interacting management activities

X
Nesting Beach Variables

Number of nests laid

#1, #2 X

Number of nests incubated in situ

#1, #3

Number of nests relocated to corrals

#1

Number of nests relocated to incubation facility

Location of nests relative to artificial lights

#2

Number of eggs*turtle-1*clutch-1

X

Number of eggs*turtle-1*year-1

X

Number of clutches*turtle-1*year-1

X

Number of tracks on nesting beach

#2 X

Number of nesting females observed

#2 X

Number of hatchlings produced in corrals

#1 X

Number of hatchlings produced in situ

#3 X

Number of hatchlings produced in incubation

X

Hatching success of nests incubated in situ

#1, #3 X

Hatching success of nests relocated to corrals

#1 X

Hatching success of nests relocated to

X

Hatchling orientation

#2

Hatchling sex ratio

#1

Number of remigrants nesting

X

Remigration interval (years)

X

Number of first time breeders nesting

X

Number of nests predated

#3 X

Number of predators removed

#3 #3

Number of functioning corrals

#1

Beach light levels

#2 #2
Suggested Citation:"Sea Turtle Restoration Monitoring." National Academies of Sciences, Engineering, and Medicine. 2017. Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico. Washington, DC: The National Academies Press. doi: 10.17226/23476.
×
Monitoring Purpose
Construction Performance Program-level
Potential Monitoring Metrics Examples Examples Suggested
In-water Variables

Ageclass- and sex-specific foraging-ground abundance

X

Ageclass- and sex-specific survival probabilities

Ageclass- and sex-specific dispersal

Growth rate

Age at sexual maturity

Adult sex ratio

Number of turtles counted at the surface

#5 X

Number of turtles counted underwater

#5 X

Number of turtles captured per unit effort

#5 X

Number of turtles killed per unit effort

#5

Number of turtles stranded alive

#4 X

Number of turtles stranded alive, rehabilitated and not returned to the wild

#4

Number of turtles stranded alive, rehabilitated and returned to the wild

#4

Number of turtles stranded dead

#4

Number of mortalities due to known causes

Number of mortalities due to commercial and recreational fisheries

Number of mortalities due to unknown causes

Number of fishing vessels per fishery

#5

Number of fishing vessels per fishery using bycatch reduction tools and/or methods

Number of fishing vessels per fishery not using bycatch reduction tools and/or methods

Ecosystem Services

Existence value

Wildlife watching

SOURCES: Eckert et al., 1999; Ehrhart and Ogren, 1999; Schroeder and Murphy, 1999; Heppell et al., 2003; NRC, 2010; Bjorndal et al., 2011; DWH NRDA Trustees, 2016.

NOTES: Examples are provided to illustrate linkages between restoration situations/objectives and appropriate metrics. Example #1 (linkages shown in the table by “#1”) is to construct corrals on sea turtle nesting beaches; Example #2 is to reduce artificial lights on sea turtle nesting beaches; Example #3 is to control predators on sea turtle nesting beaches; Example #4 is to restore stranded turtles; and Example #5 is to reduce fisheries bycatch. The “X” symbol indicates metrics that are suggested by the committee as appropriate to sample across multiple projects at a program, region, or Gulf-wide scale.

Suggested Citation:"Sea Turtle Restoration Monitoring." National Academies of Sciences, Engineering, and Medicine. 2017. Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico. Washington, DC: The National Academies Press. doi: 10.17226/23476.
×

Monitoring Planning Considerations

Project planning prior to implementation is critical and involves defining project goals and specific measurable objectives as well as considering location, scope, timing, feasibility, data collection methods, and evaluation. Good practice is for projects to be located in areas where sea turtles occur and if possible, where long-term data are available to provide estimates of their abundance prior to project implementation. On land, documented nesting beaches with long-term projects already established provide the best opportunity for monitoring nesting females, eggs, and hatchlings. In the water, long-term monitoring and research projects already established provide the best opportunity for monitoring sea turtles at sea, however few exist. New in-water monitoring projects are designed to determine if restoration efforts on land and at sea (e.g., to reduce bycatch) are effectively enhancing the in-water life stages of sea turtles. These projects would benefit from initiation and location in documented sea turtle feeding grounds (e.g., seagrass patches or beds for juvenile turtles) and/or migratory corridors, and in areas where turtles are regularly captured in recreational fisheries (e.g., hook and line fishing). Good practice is for projects that will monitor incidental capture of sea turtles in commercial fisheries to be located on relevant vessels, and at a sufficient level of observer effort, in the fisheries that are known to interact with sea turtles. Coordinated data collection among all projects on land and in water is critical to ensure the relevant data are collected and that data collection methods are standardized among sites.

Construction Monitoring

Monitoring to determine if project activities are being implemented according to initial direction, requirements, and standards is fairly straight-forward and considered good practice for all types of planned sea turtle restoration projects. The type of monitoring, parameters measured, and timeframe for construction monitoring will vary according to the project activity and objectives. For example, if corrals will be constructed to protect sea turtle eggs, then construction monitoring might entail measuring the post-construction amount of beach protected, the location of the corral relative to the high tide line, and the density of vegetation in the corral. For projects that will facilitate rapid response to episodic mass stranding events (potentially in coordination with marine mammal stranding response) and rely on the use of mobile and temporary shelter for sea turtles, construction monitoring will require design and construction of such units customized to the field environments in which they will be deployed.

Performance Monitoring

For sea turtle restoration, performance monitoring to determine the effectiveness of restoration to meet objectives requires measuring changes over time, and is a little more difficult and costly to undertake than construction monitoring. Project objectives may range from increasing hatchling recruitment by relocating eggs to a protected area to reducing disorientation of turtles by minimizing artificial lights on nesting beaches. These projects require a variety of measurements over relevant time and spatial scales and will vary according to the project type and objectives. There are numerous metrics routinely used on sea turtle nesting beaches and in the water to estimate sea turtle abundance. These range from visual counts of eggs, nests, hatchlings, turtle tracks, and individual nesting females on land to the capture of turtles in the water using nets (Eckert et al., 1999). A rigorous and robust sampling design requires repeated measurements over a sufficient time period that is scaled to the objectives of each specific project (see Chapter 3). Single project performance monitoring time-scales of multiple years can evaluate the impacts of restoration activities. Determining the effectiveness of restoration activities applied over multiple sea turtle restoration projects will take decades if current practices are used to assess sea turtle population status and trends, and it will not be possible to determine the relative contributions of individual projects to observed changes. It is possible, however, to identify population improvements by analyzing changes in age or size structure, as well as other population indices as recommended in the NRC (2010) report. Further metrics of sea turtle status and trends are described in Table II.5.

Much of the project-level baseline data are already available for sea turtle populations in the Gulf. For projects on land, long-term programs to monitor adult female Kemp’s ridleys (Lepidochelys kempii), loggerhead (Caretta caretta), and green turtles (Chelonia mydas) at nesting beaches provide baseline information including direct counts of nesting females, or counts of their tracks and nests. There are also several in-water sea turtle projects in the Gulf of Mexico that can provide useful baseline data to assess sea turtle population trends. Consistency

Suggested Citation:"Sea Turtle Restoration Monitoring." National Academies of Sciences, Engineering, and Medicine. 2017. Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico. Washington, DC: The National Academies Press. doi: 10.17226/23476.
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and standardization of methods used to collect data prior to project implementation enables comparison with data collected after implementation.

Monitoring for Adaptive Management

Monitoring for adaptive management may be achievable for certain types of individual projects. The feedback obtained from project monitoring can inform whether activities are achieving the intended project-specific goals and objectives. For example, projects to reduce hatchling disorientation on nesting beaches will monitor hatchling dispersal after artificial lights have been modified, and ideally compare this metric with baseline information to assess any change. If hatchling disorientation continues, additional management measures to further reduce artificial lights can be implemented and evaluated. Similarly, projects aimed at increasing hatchling recruitment by relocating eggs to corrals or controlling predators will monitor metrics such as hatchling abundance, production, and survival before and after restoration and/or compared to wild, unmanipulated nests to estimate the extent of change due to restoration at a population level, beyond individual nests. If hatchling production does not increase to meet stated objectives, then additional management measures to increase hatching success can be implemented if the causes for egg and/or hatchling mortality are understood.

Monitoring for adaptive management across multiple projects to determine if activities are restoring sea turtles in the Gulf of Mexico is possible despite the decision-critical uncertainties noted earlier, and the high uncertainty of key parameter values that limit the ability to fully interpret the changes in sea turtle population abundance. This will require significant planning, resources, and cooperation and communication among the multiple agencies with oversight for restoration.

In particular, more effective approaches for monitoring and assessing Gulf of Mexico sea turtle restoration activities will have to be used to overcome some of the key uncertainties in the system conceptual model and the limitations of current monitoring practices used to assess sea turtle status and trends. These approaches include:

To evaluate sea turtle trends in abundance and determine causes of population change and the relative effects of various restoration projects, further integration of quantitative population models with demographic information is needed (NRC, 2010; Bjorndal et al., 2011). Researchers already gather data from multiple sources and analyze them with the aim of finding correlations. This work would be enhanced by implementing the data management, stewardship, and sharing recommendations provided in Chapter 5, as well as further consideration of the interconnectedness and cause/effect relationships between various restoration and management actions and outcomes, as described in Chapter 6. Without these steps, it will be difficult to diagnose potential causes of population trends and determine the relative impacts of various restoration projects and approaches.

New Observing Technologies

New approaches to monitor sea turtle movement, habitat use, and behavior have been developed, are in limited use, and promise to overcome many of the key limitations of conventional methods used to track the distribution and abundance of highly mobile marine animals with life stages that are difficult to access. Conventional tracking methods rely on satellite or radio telemetry. Both methods are very expensive relative to the value of their outcomes, and rely on sea turtles spending time at the surface of the water in order to receive a signal, process it, and calculate an accurate location. Sea turtles spend very little time at the surface and as a result these conventional tracking methods do not provide robust information; location accuracy is estimated and error rates can be quite high (Plotkin, 1998). Underwater acoustic telemetry has been used to track sea turtles for more than two decades, but has never been in wide use because the cost of following turtles with mobile

Suggested Citation:"Sea Turtle Restoration Monitoring." National Academies of Sciences, Engineering, and Medicine. 2017. Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico. Washington, DC: The National Academies Press. doi: 10.17226/23476.
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acoustic receivers in boats made this endeavor expensive and impractical.

New underwater acoustic technology using fixed acoustic arrays and buoys or mobile gliders provides a low cost alternative and is changing the way we study the oceans and manage marine resources. Acoustic transmitters are now available at a fraction of the cost they once were, are smaller, can be coded to identify individuals, have a long battery life (years), and there is no location error—a signal is either received or not received at a fixed location. This emerging technology can provide information on sea turtle movements and density (Blumenthal et al., 2009) and can also be used to measure vital rates important to sea turtle assessments (e.g., survivorship of juvenile life stages) that traditional monitoring methods are currently unable to estimate. The Gulf of Mexico Coastal Ocean Observing System1 has a coordinated network of acoustic observing systems, infrastructure, and platforms that can be used to track sea turtles in the Gulf of Mexico and provides a viable opportunity to reduce cost constraints. Because the sample sizes possible from satellite and acoustic tagging are generally not large enough to determine vital rates, a potential option to estimate survival is introducing inexpensive mortality tags to mark and recapture sea turtles.

EXAMPLE OF HOW MONITORING CAN AID SEA TURTLE RESTORATION

Monitoring and assessment of Kemp’s ridley sea turtle (Lepidochelys kempii) abundance, based on the number of nests counted, illustrates the limitations of relying on just nesting beach monitoring to interpret population change. Kemp’s ridley is a critically endangered species that breeds only in the Gulf of Mexico and spends the majority of its life cycle there. After the population dropped to a few hundred in 1985, restoration through protection of nesting beaches and new fishing technology and restrictions led to an increase in the number of Kemp’s ridleys in Mexico and Texas, an expansion of their nesting range in the Gulf of Mexico, and exponential growth through 2009 to nearly 10,000 turtles (Heppell et al., 2007; Crowder and Heppell, 2011). However, because many of the key demographic parameters for Kemp’s ridley are unknown, the relative contribution of each conservation action toward the species’ increase in abundance is currently beyond our reach.

By 2010, a significant decline in the number of Kemp’s ridley nests was detected at nesting beaches (Caillouet, 2014; Plotkin and Bernardo, 2014) and the number of nests has fluctuated since then. Demographic model predictions had forecast population growth at an estimated rate of 19% per year during 2010-2020, assuming survival rates within each life stage remained constant and egg-to-hatchling survival rate remained high (NMFS et al., 2011). Instead, the population’s pre-2010 exponential growth was interrupted (Caillouet, 2010, 2011, 2014; Crowder and Heppell, 2011; Gallaway et al., 2016). Monitoring nesting Kemp’s ridleys for more than 30 years was critical to obtain abundance estimates for the species and detect the increase from the 1990s to 2010, largely due to beach protection and increased survivorship to maturity, likely through gear improvements that have reduced bycatch. However, the absence of basic demographic information has prevented analysis of the specific actions that led to the root cause of the fluctuation in nest numbers since 2010 (i.e., reproductive output of nesting females).

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1 The Gulf of Mexico Coastal Ocean Observing System (GCOOS): http://gcoos.org.

Suggested Citation:"Sea Turtle Restoration Monitoring." National Academies of Sciences, Engineering, and Medicine. 2017. Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico. Washington, DC: The National Academies Press. doi: 10.17226/23476.
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Suggested Citation:"Sea Turtle Restoration Monitoring." National Academies of Sciences, Engineering, and Medicine. 2017. Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico. Washington, DC: The National Academies Press. doi: 10.17226/23476.
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Suggested Citation:"Sea Turtle Restoration Monitoring." National Academies of Sciences, Engineering, and Medicine. 2017. Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico. Washington, DC: The National Academies Press. doi: 10.17226/23476.
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Suggested Citation:"Sea Turtle Restoration Monitoring." National Academies of Sciences, Engineering, and Medicine. 2017. Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico. Washington, DC: The National Academies Press. doi: 10.17226/23476.
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Suggested Citation:"Sea Turtle Restoration Monitoring." National Academies of Sciences, Engineering, and Medicine. 2017. Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico. Washington, DC: The National Academies Press. doi: 10.17226/23476.
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Suggested Citation:"Sea Turtle Restoration Monitoring." National Academies of Sciences, Engineering, and Medicine. 2017. Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico. Washington, DC: The National Academies Press. doi: 10.17226/23476.
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Suggested Citation:"Sea Turtle Restoration Monitoring." National Academies of Sciences, Engineering, and Medicine. 2017. Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico. Washington, DC: The National Academies Press. doi: 10.17226/23476.
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Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico Get This Book
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Gulf Coast communities and natural resources suffered extensive direct and indirect damage as a result of the largest accidental oil spill in US history, referred to as the Deepwater Horizon (DWH) oil spill. Notably, natural resources affected by this major spill include wetlands, coastal beaches and barrier islands, coastal and marine wildlife, seagrass beds, oyster reefs, commercial fisheries, deep benthos, and coral reefs, among other habitats and species. Losses include an estimated 20% reduction in commercial fishery landings across the Gulf of Mexico and damage to as much as 1,100 linear miles of coastal salt marsh wetlands.

This historic spill is being followed by a restoration effort unparalleled in complexity and magnitude in U.S. history. Legal settlements in the wake of DWH led to the establishment of a set of programs tasked with administering and supporting DWH-related restoration in the Gulf of Mexico. In order to ensure that restoration goals are met and money is well spent, restoration monitoring and evaluation should be an integral part of those programs. However, evaluations of past restoration efforts have shown that monitoring is often inadequate or even absent.

Effective Monitoring to Evaluate Ecological Restoration in the Gulf of Mexico identifies best practices for monitoring and evaluating restoration activities to improve the performance of restoration programs and increase the effectiveness and longevity of restoration projects. This report provides general guidance for restoration monitoring, assessment, and synthesis that can be applied to most ecological restoration supported by these major programs given their similarities in restoration goals. It also offers specific guidance for a subset of habitats and taxa to be restored in the Gulf including oyster reefs, tidal wetlands, and seagrass habitats, as well as a variety of birds, sea turtles, and marine mammals.

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