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Bottom-grab samplers have long been the standard to describe nearshore marine habitats both qualitatively and quantitively. However, sediment samplers are designed to collect specific grain sizes and therefore have biases toward those sediments. Here, we discuss seafloor characterizations based on grain size analysis alone vs. grain size analysis augmented with quantitative benthic imagery. We also use both datasets to inform a prevalent benthic habitat classification system. The Coastal and Marine Ecological Classification Standard (CMECS) was used to test this hypothesis. CMECS was adopted by the federal government to standardize habitat classification in coastal U.S. waters. CMECS provides a hierarchal framework to define and interpret benthic habitats but does not prescribe specific sampling methods. Photography has been utilized for many decades in benthic ecology but has rarely been employed in habitat classification using CMECS. No study to date has quantitatively examined the benefit of incorporating benthic imagery into the classification of biotopes using CMECS. The objective of this study is to classify a roughly 1 km2 subtidal area within Herring Cove in Provincetown, MA with CMECS and quantify the benefit of augmenting classification with low-cost imagery. A benthic habitat survey of the study area included grab sampling for grain-size analysis and invertebrate taxonomy, benthic imagery, water quality sampling at 24 sampling stations, and acoustic mapping of the study area. Multivariate statistical analyses were employed to classify biotic communities and link environmental and biological data to classify biotopes. The results showed that benthic imagery improved the classification and mapping of CMECS components. Furthermore, the classification of habitats and biotopes was improved using benthic imagery data. These findings imply that the incorporation of low-cost benthic imagery is warranted in coastal benthic biotope classification and mapping studies and should be regularly adopted. This study has implications for coastal benthic ecologists classifying benthic habitats within the CMECS framework. [ABSTRACT FROM AUTHOR]

Hydraulic dredges used for bivalve harvest are known to create immediate biological and physical changes to the substrate, but the rate of recovery is often site specific and habitat specific. Hydraulic dredging for the Atlantic surfclam Spisula solidissima (Dillwyn. 1817) occurred off Provincetown, MA, from November 2014 through April 2015. Acoustic surveys following the dredge activity were conducted in 2015 (June-August) with a phase-measuring sidescan sonar, yielding colocated sidescan backscatter and swath bathymetry. Dredge tracks were documented in 7.9% (402,309 [m.sup.2]) of the 5.1 [km.sup.2] surveyed. The survey area was divided into 10 x 10 m grid cells, and track density was calculated within each grid by the aggregated count of dredge tracks within each grid cell. The resulting track densities ranged between 0% and 53%. On October 23, 2017, 875 days after the 2015 hydraulic clamming season, a subset (1.05 [km.sup.2] ~20%) of the same area was acoustically surveyed. The 2017 survey (1.05 [km.sup.2]) revealed that dredge tracks covered a total area of 9,784 [m.sup.2] at a density of 0%-24%. Initial areas (2015) with dredge track density greater than 10% had not fully recovered in 2017, and the rate of dredge tracks remaining was proportional to disturbance (linear regression; r = 0.95; F = 110.6; df = 1,7; P < 0.001; SE = 0.206). The adjacent dynamic shoreline and the persistence of dredge tracks reinforce the idea that nearshore energy regimes should not be assumed based solely on more visible shoreline processes. KEY WORDS: hydraulic dredging, sidescan sonar, clamming, disturbance, INTRODUCTION The immediate biological and physical impacts of hydraulic clamming are known to be high across a variety of habitats (O'Neill & Ivanovic 2016, Hiddink et al. 2017). This method [...]

Abandoned, lost, or otherwise discarded fishing gear (ALDFG) is a by‐product of many fisheries. ALDFG impacts extend beyond the targeted species and include by‐catch, habitat degradation, and increased plastic in the environment. In particular ALDFG such as lobster gear attracts a succession of fouling organisms, increasing species diversity and productivity.In Cape Cod Bay, Massachusetts, USA, a seasonal lobster gear closure occurs for the protection of North Atlantic right whales (Eubalaena glacialis), allowing for the removal of ALDFG. In this study, the percentage cover of fouling organisms on recovered gear was used to model the age of the recovered gear (of indeterminate age because of missing tags).Between 2017 and 2021, a total of 379 traps were photo documented, of which 223 were of known age (1–22 years) and 156 were of unknown age. The age of the unknown traps was modelled utilizing a random forest algorithm using traps with a known age as a training library.High correlations between modelled ages and known ages (R2 = 0.634, P < 0.001*) slightly underestimated the age of the traps by 1.2–1.8 years, but are sufficient for developing an age distribution. The majority (79%) of traps were recovered off Provincetown and averaged 10–11 years old. Approximately 50% of the traps recovered in Cape Cod Bay were deposited or lost between 2005 and 2010.Calculating the age of ALDFG aids in determining the loss rate of gear and in identifying high concentrations of untended gear that can be recycled or reused. This analysis allows practitioners to understand the scale of the problem, helps quantify the quantity of gear in the ocean, and helps identify the areas most affected. This information improves the effectiveness of removal efforts by focusing on discrete areas of recurring and recent gear loss. [ABSTRACT FROM AUTHOR]

Hydraulic dredging for shellfish is known to create some of the highest levels of disturbance, affecting the benthic microfaunal community and the physical characteristics of the substrate. Properly conducted benthic habitat assessments are complex and time consuming, resulting in assessments not being conducted increasing the uncertainty in post impact studies. Hydraulic dredging for Atlantic surfclams (Spisula soldidissima) took place at Herring Cove, Massachusetts in the winter of 2014–2015 resulting in areas of high impact disturbance of the seafloor. Surveys conducted in the summer of 2015 included hydroacoustics, benthic invertebrate sampling, video, and grain size analysis for the creation of a habitat map of Herring Cove. The four habitats (A–D) identified were a mix of sand, shell, cobble, algae, and eelgrass. Habitat type “D” is a mix of sand, algae and cobble material and occurred at 12 of 18 stations. These 12 stations were distributed across areas of “high” (n = 4), “low” (n = 2), and “no” (n = 6) hydraulic dredge disturbance. Once habitat was accounted for, benthic invertebrate community structure varied significantly (Analysis of similarity; significance level of sample statistic: 0.3%) between areas of “high”, “low” to “no” disturbance. Areas of “low” to “no” dredge track coverage contained high abundances of bivalves, echinoderms, and isopods, whereas highly disturbed areas had highest abundances of polychaetes and oligochaetes. Future mapping efforts, especially surveys with biological components, need to include and quantify the level, type and spatial distribution of anthropogenic alterations. More attention should be given to “reference maps” instead of “baseline maps”. The latter of which omits to acknowledge pre-existing anthropogenic disturbances and has the potential to skew monitoring of restoration and management efforts.

Shark nursery areas are widely regarded as essential habitats for the growth and survival of young individuals. The effective management and protection of shark nursery habitat are contingent upon a clear understanding of how individual species utilize such habitat both spatially and temporally. Although shark nurseries have been identified in the Caribbean, this information is generally lacking. From 2006 to 2012, we used passive acoustic telemetry to monitor the presence, movements, and habitat use of 65 juvenile blacktip sharks (Carcharhinus limbatus) and 42 juvenile lemon sharks (Negaprion brevirostris) within Fish Bay and Coral Bay, two shark nurseries in St. John, United States Virgin Islands. Both species were present in each bay during all months of the year, but abundance peaked during the summer (June-September). Although telemetry data indicated that blacktip and lemon sharks moved throughout each embayment, each species exhibited strong site fidelity to core areas across all years of the study. Habitat partitioning was observed in both nurseries as blacktip sharks generally occurred in areas characterized by water depths of 1.5-6 m with seagrass and sand/mud substrate, while lemon sharks remained in close proximity to or within shallow (, Introduction Sharks are important members of marine communities capable of exerting strong top-down forces over large spatial and temporal scales (Ferretti et al. 2010). Within tropical marine communities, they have [...]