Florida Keys Research Articles

Reef site and habitat influence effectiveness of Acropora palmata restoration and its microbiome in the Florida Keys

AbstractThe success of coral restoration for the critically endangered Acropora palmata is understudied. Here, we examined how habitat and coral microbiomes influenced survivorship in four genets of A. palmata outplanted in three reefs. A. palmata microbiomes were correlated to reef and habitat and minimally to coral genet. Carysfort Reef exhibited the lowest survivorship which correlated to lower current velocity and a higher relative abundance of Rhodobacterales in A. palmata. Higher survivorship was present at Pickles Reef which correlated to the highest current velocity, and at North Dry Rocks with the shallowest outplant depth. Habitat factors driven by time of year such as higher levels of nitrate, nitrite, and temperature also correlated with a relative increase in a putative pathogen, Alteromonadales, and a decrease in an uncharacterized core bacteria. We suggest outplanting at sites with high currents, lower depths, and at lower concentrations of nitrate/nitrite to increase A. palmata survivorship.

DNA sequencing reveals higher taxonomic diversity of coralline algae (Corallinales and Hapalidiales, Rhodophyta) in the tropical western North Atlantic that complicates ecological studies

Abstract Understanding of non-geniculate coralline algal (NGCA) diversity, prevalence, and distribution in the tropical western North Atlantic is currently limited by reliance on morphological and anatomical features that are inadequate for species identifications. Reef surveys from two study sites, the Florida Keys (Florida, USA) and Roatán (Honduras), provided prevalence data for the main benthic organisms as well as relative abundance for NGCA genera. NGCA collected during these surveys and from additional sites and depths were identified using DNA sequences from two plastid genes, psbA and rbcL, and two nuclear genes, SSU and LSU, and supported by morphological and anatomical descriptions. Bayesian and Maximum Likelihood phylogenetic analyses, along with species delimitation and genetic distance methods, resolved 11 genera within two orders. Within the Corallinales, the genera Dawsoniolithon, Porolithon and Spongites each had one species, Harveylithon and Lithophyllum had two, Titanoderma three, Hydrolithon four, Neogoniolithon eight, and an unknown genus within the subfamily Neogoniolithoideae had 11 putative species. Within the Hapalidiales, the genera Phymatolithon and Roseolithon each had one species. This study reinforces the inability of morphological and anatomical features to distinguish NGCA species in the tropical western North Atlantic, resulting in substantial underestimations of species richness and diversity.

High Prevalence of Sarcocystis in a Collapsed Black Rat (Rattus rattus) Population from the Florida Keys.

We collected and screened black rats (Rattus rattus) in Key Largo, Florida, USA, to determine the potential role of disease or parasites in the collapse of the local population. Rats appeared healthy, but 94% (n=15/16) tested positive for Sarcocystis sp. The partial 18S rRNA gene sequence was 98.7-99.7% similar to a strain of Sarcocystis zuoi that is now considered a strain of the newly described Sarcocystis kani within the larger S. zuoi species complex that contains numerous new species. These Sarcocystis spp. use Asian snakes as definitive hosts and rodents, shrews, or tree shrews as intermediate hosts. Pythons are the definitive host for several Sarcocystis spp. in Asia, including a related parasite (Sarcocystis singaporensis) that has been used as a biologic control agent for Rattus spp. in southeast Asia. It is probable that increasing numbers of invasive Burmese pythons (Python bivittatus) in the Florida Keys are contributing to the spread of this parasite in addition to imposing predation pressure on both rodents and native snakes. As such, further surveillance and molecular and morphologic characterization of parasites from rodents and snakes in south Florida should be prioritized.

Decrypting Corals: Does Regulatory Evolution Underlie Environmental Specialisation of Coral Cryptic Lineages?

A recent sequencing study has shown that two common Caribbean corals, Montastraea cavernosa and Siderastrea siderea, each consist of four genetically distinct lineages in the Florida Keys. These lineages are specialised to a certain depth and, to a lesser extent, to nearshore or offshore habitats. We hypothesised that the lineages' environmental specialisation is at least in part due to regulatory evolution, which would manifest as the emergence of groups of coregulated genes ('modules') demonstrating lineage-specific responses to different reef environments. Our hypothesis also predicted that genes belonging to such modules would show greater genetic divergence between lineages than other genes. Contrary to these expectations, responses of cryptic lineages to natural environmental variation were essentially the same at the genome-wide gene coexpression network level, with much fewer differences in gene expression between lineages compared to between habitats. Moreover, none of the identified coregulated gene expression modules exhibit elevated genetic divergence between lineages. Possible explanations of these unexpected results range from the leading role of algal symbionts and/or microbiome in adaptation to strong action of spatially varying selection equalising gene expression patterns despite different genetic background. We discuss how future studies could assist in discriminating between these possibilities.

Addressing data gaps in the abundance and distribution of Wilson's Plover (Anarhynchus wilsonia) in the Florida Keys

Addressing data gaps in the abundance and distribution of Wilson's Plover (Anarhynchus wilsonia) in the Florida Keys

The first record of the alpheid shrimp Automate isabelae Ramos-Tafur, 2018 from Brazil (Decapoda: Caridea)

The alpheid shrimp Automate isabelae Ramos-Tafur, 2018 was described based on material found in stomachs of the lane snapper Lutjanus synagris (L.) in the Florida Keys and south-western coast of Florida, USA (24°N). In the present study, A. isabelae is reported from Araçá Bay, São Sebastião, São Paulo, Brazil (23°S), the first time since its original description, representing the first record of the species for the south-western Atlantic. The colour pattern of A. isabelae is illustrated for the first time. The differentiating characters between A. isabelae and its presumed eastern Pacific sister species A. rugosa Coutière, 1902 are discussed.

Appendage pigmentation and temperature acclimation correlate with survival during acute heat stress in the upside-down jellyfish, Cassiopea xamachana

IntroductionUpside-down jellyfish (Cassiopea sp.) are highly tolerant to multiple abiotic stressors, including fluctuating temperatures associated with shallow marine habitats. This resilience may underlie the ability of Cassiopea sp. to inhabit a wide variety of tropical habitats across the globe. Additionally, Cassiopea sp. are marked by a conspicuous array of appendage coloration; individual medusae vary in the hue and number of oral appendages, which are often strikingly blue. The function of this coloration is not understood. We aimed to understand how extrinsic (temperature, location) and intrinsic (host color) factors may shape thermal tolerance.MethodsAdult Cassiopea xamachana were collected from two sites that vary in daily temperature range within the Florida Keys and were subjected to acute lethal heat stress. To quantify a whole-organism response to heat, we measured changes in bell pulsation, which likely plays a role in feeding, oxygen exchange, and symbiont uptake. Finally, color morphs were acclimated at either ambient (26°C) or elevated (33°C) temperatures.ResultsC. xamachana from two locations that vary in thermal range do not exhibit different responses to heat, suggesting that temperature fluctuations do not prime individuals for higher thermal tolerance. Additionally, C. xamachana with blue appendages survived significantly higher temperatures and exhibited less change in bell pulsation rates compared to non-blue individuals. We found that acclimation at 33°C, as well as appendage color in each treatment, led to higher survival under acute heat stress.DiscussionThese findings highlight the importance of temperature and coloration in Cassiopea xamachana resilience during heat stress.

Heat Stress Impacts on Coral Reef Ecosystems and Communities: An Evaluation of Visitor Perceptions, Behaviors and Substitution Effects in the Florida Keys National Marine Sanctuary, USA

Evaluating the effects of environmental events across both biophysical and social dimensions is important in establishing a holistic view of such events. This study focuses on the impact of a devastating heat stress incident that occurred in many locations across the Caribbean region and South Atlantic during the 2023 summer season. The survey and focus of data collection was within Monroe County, a unique nature-based setting south of Miami, Florida, USA. The impact of the heat wave is still being calculated at the time of submission of this paper, but indications are that there was a major negative impact. The survey and data collection sought to understand recreationists’ perceptions, knowledge, and behavior changes as result of the heat stress impact in the Florida Keys. Respondents were interviewed during community workshops in person and through an online sample of boating/angler license holders. The results indicated a change in behavior by some respondents, which may have a longer-term economic impact, along with trends of satisfaction with outdoor recreation over time. This rapid survey method can be applied to future scenarios where social and economic data are needed to fully contextualize environmental impacts in addition to biological endpoints.

Shifting patterns in parrotfish corallivory after 12 years of decline on coral depauperate reefs in the Florida Keys, USA

Shifting patterns in parrotfish corallivory after 12 years of decline on coral depauperate reefs in the Florida Keys, USA

Vulnerability of endemic insular mole skinks to sea‐level rise

AbstractAlthough coastal islands are home to many endemic species, they are also at risk of inundation from storm surge and sea level rise. Three subspecies of mole skink (Plestiodon egregius egregius, P. e. insularis, and the Egmont Key Mole Skink known from a single occurrence) occur on a small number of islands off the Gulf Coast of Florida, USA. We used the most recent sea level rise projections and the latest storm surge simulation data to predict impacts to habitat for insular mole skinks in Florida from 2030 to 2150. Our models predicted that in <100 years (by 2100; intermediate sea level rise scenario; ~1.08–1.15 m sea level rise), >78% of preferred habitat for the Florida Keys Mole Skink, >65% of preferred habitat for the Cedar Key Mole Skink, and >36% of preferred habitat for the Egmont Key Mole Skink will be inundated from sea level rise. Storm surge from tropical cyclones presents a more immediate risk to insular mole skink habitat: our models predicted that between 58% and 75% of Florida Keys Mole Skink habitat is at risk of being submerged under an average maximum of between 0.60 (SD = 0.86) and 0.98 (SD = 0.36) m of storm surge water for a category 1 storm, and the amount of habitat predicted to be impacted increases for higher intensity storms. Our models predicted similar trends for Cedar Key and Egmont Key Mole Skink habitat. Given current sea level rise projections, our models predicted that all three subspecies could be extinct by 2140 due to habitat inundation. There remains uncertainty about how species and ecosystems will respond to sea level rise, thus research to fill these gaps could help mitigate the effects of sea level rise in areas most vulnerable to the effects of climate change.

The Efficiency of Phosphate Removal via Shallow Wastewater Injection into a Saline Carbonate Aquifer.

Wastewater-derived phosphate contributes to eutrophication if the phosphate is not efficiently removed before it is discharged to surface waters. In the Florida Keys (USA), shallow injection of treated wastewater into saline limestone aquifers is a common mode of wastewater disposal. We assessed the possibility of efficient and permanent phosphate removal following injection at a wastewater treatment facility in Marathon, Florida. The concentrations of nutrients, dissolved ions, and anthropogenic compounds in groundwater and nearshore waters were monitored over two years, as was the progression of a patch of fluorescent dye emplaced by the wastewater injection well. The density contrast between the wastewater effluent and saline groundwater caused the effluent plume to buoy to the shallow subsurface near the injection well. Soluble reactive phosphorus (SRP) and sucralose were both detected in nearshore waters, indicating incomplete removal of contaminants. However, ∼75% of the SRP is removed from the plume in the first 10 days of transit by adsorption followed by a slower removal mechanism, bringing the P removal efficiency above 90%. A positive relationship between excess calcium and phosphate removal efficiency, together with high levels of calcium phosphate mineral supersaturation, supports calcite dissolution followed by calcium phosphate mineralization as this slower removal process.

Hurricane Irma Linked to Coral Skeletal Density Shifts on the Florida Keys Reef Tract.

Coral reefs are at risk due to various global and local anthropogenic stressors that impact the health of reef ecosystems worldwide. The most recent climate models predict that climate change will increase the frequency and intensity of tropical storms. This increased storm occurrence and strength will likely compromise coral reef structures and habitats for reef-dwelling organisms, including across the Florida Keys Reef Tract (FKRT), the most extensive tropical reef system along the US coast. While several recent studies reveal the chronic impacts of tropical storms on corals, relatively little is known about the effects of major storm events on coral growth and how these effects vary over spatiotemporal scales. Here, I characterize the skeletal growth of two common Caribbean reef-building coral species, Siderastrea siderea and Pseudodiploria strigosa, before and after Hurricane Irma to investigate the storm's impact on coral skeletal growth on inner and outer reefs of the FKRT. Coral cores were extracted from both species at four inner and four outer reef sites in May 2015, before Hurricane Irma struck the Florida Keys in September 2017. Subsequently, 33 micro-cores were collected in May 2019, two years after the storm traversed our previously cored coral colonies. A three-way ANOVA model with storm, species, and reef location as the three factors was used to assess the impact of the storm on each of three growth parameters: skeletal density, linear extension, and calcification rates. Results reveal no difference in the coral annual skeletal growth parameters pre- and post-Hurricane Irma, although previously quantified differences in these growth parameters across species and location were observed. However, analysis of the "yearly" change in annual skeletal growth parameters showed significant differences in skeletal density across groups before and after Hurricane Irma, but not for linear extension and calcification rates. Our findings improve an understanding of the impacts of tropical storms on coral skeletal growth and offer new insights into how we can employ corals' innate growth capacities to help conserve coral reefs under climate change.

Long-term patterns and trends in water column biogeochemistry in a changing environment

Water column nutrient concentrations and autotrophy in oligotrophic ecosystems are sensitive to eutrophication and other long-term environmental changes and disturbances. Disturbance can be defined as an event or process that changes the structure and response of an ecosystem to other environmental drivers. The role disturbance plays in regulating ecosystem functions is challenging because the effect of the disturbance can vary in magnitude, duration, and extent spatially and temporally. We measured changes in total nitrogen (TN), dissolved inorganic nutrient (DIN), total phosphorus (TP), soluble reactive phosphorus (SRP), total organic carbon (TOC), and chlorophyll-a (Chl-a) concentrations throughout the Everglades, Florida Bay, and the Florida Keys. This region has been subjected to a variety of natural and anthropogenic disturbances including tropical storms, fires, eutrophication, and rapid increases in water levels from sea-level rise and freshwater restoration. We hypothesized that the rate of change in water quality would be greatest in the coastal ecotone where disturbance frequencies and marine P concentrations are highest, and in freshwater marshes closest to hydrologic changes from restoration. We applied trend analyses on multi-decadal data (1996–2019) collected from 461 locations distributed from inland freshwater Everglades (ridge and slough) to outer marine reefs along the Florida Keys, USA. Total Organic Carbon decreased throughout the study area and was the only parameter with a systematic trend throughout the study area. All other parameters had spatially heterogeneous patterns in long-term trends. Results indicate more variability across a large spatial and temporal extent associated with changes in biogeochemical indicators and water quality conditions. Chemical and biological changes in oligotrophic ecosystems are important indicators of environmental change, and our regional ridge-to-reef assessment revealed ecosystem-specific responses to both long-term environmental changes and disturbance legacies.

Re-evaluating Marine Isotope Stage 5a paleo-sea-level trends from across the Florida Keys reef tract

Unraveling how Global Mean Sea Level (GMSL) fluctuated during past warm periods can improve our understanding of linkages between sea-level fluctuations, orbital forcing, and ice-sheet dynamics. Current estimates of GMSL for Marine Isotope Stages (MIS) 5a and 5c — two warm intervals following the relatively well-documented MIS 5e — contain meters of uncertainty and fewer data due to several challenges. These challenges include concealment of datable in-situ coral facies by MIS 1 deposits and inaccessibility due to submergence by modern sea level. We present a comprehensive dataset based on U–Th dating and stratigraphic correlation of 23 cores totaling over 170 m of recovered coral-reef deposits across the tectonically stable Florida Keys Reef Tract (FKRT). Following detailed facies descriptions, 34 in-situ, minimally altered aragonitic coral samples (≤2.7% calcite) below the Holocene-Pleistocene boundary were targeted for U–Th geochronology. Fourteen closed-system coral U–Th ages from MIS 5a include the commonly used sea-level indicator Acropora palmata, but also the massive coral taxa Pseudodiploria strigosa, Siderastrea siderea, Orbicella spp., and Porites astreoides. Dating yielded ages in the range of 88–81 ka (average 2σ uncertainty of less than 200 years). These ages suggest MIS 5a reef initiation at ∼88 ka BP, a peak near 83 ka with minimum elevations between −6.0 ± 0.5 and −5.6 ± 0.5 m MSL (2σ uncertainty and subsidence-corrected), and reef termination and sea-level fall by ∼81 ka BP. Notably, the range of peak MIS 5a relative sea-level estimates of −6.5 to −5.1 m MSL are more than 2 m shallower (higher) than previous estimates of −11 to −9 m. Our higher resolution regional sea-level reconstruction across four subregions of the Florida Keys reef tract aligns with changes in July insolation at 65° N: a trend that most other records, such as deep-sea sediments, do not have the accuracy and precision to resolve. Three massive coral samples from MIS 5c, consisting of Pseudodiploria clivosa, and Orbicella spp., yielded ages in the range of 104 to 99 ka (average 2σ uncertainty less than 200 years); however, because only one sample met the closed-system criteria, our ability to estimate MIS 5c sea level is relatively limited. More empirical estimates of sea-level from the MIS 5a and MIS 5c intervals based on numerical dating of reliable local sea-level constraints are critical for GMSL calculations and relating changes in sea-level amplitude and timing to global ice volume modeling and glacio-isostatic effects, all of which can improve predictions of future sea-level changes in coastal regions.

Marine Debris Harbor Unique, yet Functionally Similar Cryptofauna Communities.

Human-made debris is entering the ocean at alarming rates. These artificial structures are becoming habitats for small marine taxa known as cryptofauna. Cryptofauna are among the most essential reef taxa; however, little is known about these organisms, let alone their fate considering degrading coral reefs and increasing anthropogenic disturbance. The current study explores differences in naturally occurring cryptofauna biodiversity compared to those inhabiting benthic marine debris. To explore this difference, we measured invertebrate diversity from autonomous reef monitoring structures (ARMS) located on patch reefs along the middle Florida Keys reef tract. ARMS were used as a proxy for natural structure to compare to marine debris removed from five reef locations. Plastic debris was the most abundant of all the debris material collected. Wood and concrete were identified as covariates since they are sourced from wooden lobster traps. Taxa diversity varied significantly between ARMS and debris, indicating that each structural unit contained significantly different and diverse communities. The most influential taxa identified included commensal shrimps, hermit crabs, brittle stars, segmented worms, and several families of crabs. Additionally, while functional richness increased with taxa richness for ARMS communities, debris communities showed decreasing functional richness and high functional similarity, suggesting a specialization of debris-specific taxa. Overall, these data assist in better understanding of the marine community ecology surrounding anthropogenic marine debris for future debris removal and management practices for comprehensive reef health.

First U.S. vascular plant extirpation linked to sea level rise? Pilosocereus millspaughii (Cactaceae) in the Florida Keys, U.S.A.

The global biodiversity crisis affects species across all continents and taxonomic groups. Direct destruction of species and habitats has been a primary driver of declines, though climate change and associated sea level rise are expected to accelerate loss. The flora of low-lying, relatively isolated islands is especially threatened when high species richness intersects with vulnerability to sea level rise. The Florida Keys represent a hotspot for cactus diversity in the eastern United States, with eight species recognized, three of which are endemic to the islands. Though not endemic to the islands, the Key Largo tree cactus (Pilosocereus millspaughii) was known in the United States from only a single population in the Florida Keys. Its decline and imminent extirpation correspond with rising sea levels in the region. The other cacti in the region, and all rare plants in the Florida Keys, are threatened with a similar fate.

Cryptic diversity of shallow and mesophotic Stephanocoenia intersepta corals across Florida Keys National Marine Sanctuary.

Population genetic analyses can provide useful data on species' regional connectivity and diversity which can inform conservation and restoration efforts. In this study, we quantified the genetic connectivity and diversity of Stephanocoenia intersepta corals from shallow (<30 m) to mesophotic (30-45 m) depths across Florida Keys National Marine Sanctuary. We generated single nucleotide polymorphism (SNP) markers to identify genetic structuring of shallow and mesophotic S. intersepta corals. We uncovered four distinct, cryptic genetic lineages with varying levels of depth-specificity. Shallow-specific lineages exhibited lower heterozygosity and higher inbreeding relative to depth-generalist lineages found across both shallow and mesophotic reefs. Estimation of recent genetic migration rates demonstrated that mesophotic sites are more prolific sources than shallow sites, particularly in the Lower Keys and Upper Keys. Additionally, we compared endosymbiotic Symbiodiniaceae among sampled S. intersepta using the ITS2 region and SYMPORTAL analysis framework, identifying symbionts from the genera Symbiodinium, Breviolum, and Cladocopium. Symbiodiniaceae varied significantly across depth and location and exhibited significant, but weak correlation with host lineage and genotype. Together, these data demonstrate that despite population genetic structuring across depth, some mesophotic populations may provide refuge for shallow populations moving forward and remain important contributors to the overall genetic diversity of this species throughout the region. This study highlights the importance of including mesophotic as well as shallow corals in population genetic assessments and informs future science-based management, conservation, and restoration efforts within Florida Keys National Marine Sanctuary.

Comparing Ant Activity and Plants Bearing Extrafloral Nectaries in Rockland Habitats of the Florida Keys with Those of the Everglades and the Bahamas

Rocklands are present in South Florida, both on the peninsula and in the Keys. Previous work has shown that extrafloral nectaries on pine rockland plants in the Florida Everglades and surrounding areas play a role in attracting ant protectors. Species with nectaries are more abundant and ant activity greater in more recently burned pine rockland habitats compared with longer undisturbed rockland hammock forest. The floristic composition and prevailing climate of Keys rocklands differs substantially from those on the mainland, so we sought to investigate ant activity and the abundance of plants with extrafloral nectaries in Big Pine Key rockland habitats. Standard baiting methods were used to assess ant abundance and potential predation activity in hardwood hammock, shrubby pine rockland, and open pine rockland sites. Ant activity was the lowest in open pine rockland, greatest in hardwood hammock, and intermediate in shrubby pine rockland, the opposite of what has been observed in previous studies in southern peninsular Florida and on Andros, Bahamas. Sampling vegetation at these same sites revealed a larger proportion of plant species with extrafloral nectaries in the pine rocklands than the hammock, as observed previously in Everglades habitats. Possible reasons for differences in ant activity in Keys rockland habitats are discussed.

Gastric mill ossicles record chronological age in the Caribbean spiny lobster (Panulirus argus)

Information on individual age and size relationships is crucial for sustainable management of fished populations. Previous research has indicated it may be possible to directly age crustaceans by counting annular bands deposited within gastric mill ossicles. The method has been applied to multiple crustacean species; however, its applicability has been controversial because studies have shown gastric mill ossicles are reworked and/or replaced during ecdysis. Over the last 8 years, we have refined and improved upon methods of processing gastric mill ossicles and investigated the validity of this method for ageing Caribbean spiny lobster (Panulirus argus) using captive-raised animals of known age from the Florida Keys (USA). Although the biological process that creates annular bands within gastric mill ossicles remains unclear, validation of the method for P. argus based on known-age lobsters from 10 months–5.5 years old (n = 33) confirms that the deposition of bands correlates with chronological age. We compared precision and accuracy of age estimates for ossicles processed using two imaging techniques (transmitted vs. reflected light) and found that transmitted light provided the best images for ageing P. argus. The mean coefficient of variation (CV) of age estimates between two readers was 20.2 %. The consensus age estimates provided by the readers were, on average, within 0.5 years of the known age and overall, 94 % of consensus age estimates from readers were within 1 year of the known age. We also compared lobsters of the same size but different age as well as those of the same age but different size to address whether the number of endocuticular bands in the ossicle is a measure of true chronological age or simply related to the size of the animal. Our results suggest that the gastric mill ossicles record chronological age in P. argus, providing a reliable ageing method with which to inform age-based management of the Caribbean spiny lobster population. Future research is needed to understand the mechanism that controls the deposition of endocuticular bands within the crustacean gastric mill ossicles and to determine the applicability of the method for other crustaceans.

Abundance, patterns, and taxa associations of anthropogenic marine debris on reefs in the middle Florida Keys

The Florida Keys reef tract has rapidly shifted from a structurally complex, hard coral-dominated reef to a less rugose, soft coral-dominated reef. This transition has been facilitated by persistent anthropogenic stressors including recreational and commercial fishing and increased anthropogenic marine debris. During the summers of 2020–2022, benthic censuses were conducted to identify substrate and marine debris composition for 30 reefs in the middle Florida Keys. Inshore reefs contained higher rugosity, coral cover, and marine debris abundance primarily comprised of monofilament and rope from fishing traps. Plastic items (e.g., ropes and monofilament) overall had the highest species diversity. Additionally, marine debris appears to promote turf algae growth on inshore reefs. While is it not yet possible to determine if this pattern of high debris nearshore is due to proximity to onshore debris sources, accumulation due to higher rugosity snagging debris, or increased debris removal efforts offshore, these differences in marine debris types and abundances suggest variability in potential impacts of debris on marine biota on inshore versus offshore reefs. Therefore, the differential use of marine debris by associated biota should be considered in marine debris management practices.