The federal channel at Port of Miami, Florida, USA, was dredged between late 2013 and early 2015 to widen and deepen the channel. Due to the limited spatial extent of impact-assessment monitoring associated with the project, the extent of the dredging impacts on surrounding coral reefs has not been well quantified. Previously published remote sensing analyses, as well as agency and anecdotal reports suggest the most severe and largest area of sedimentation occurred on a coral reef feature referred to as the Inner Reef, particularly in the sector north of the channel. A confounding regional warm-water mass bleaching event followed by a coral disease outbreak during this same time frame made the assessment of dredging-related impacts to coral reefs adjacent to the federal channel difficult but still feasible. The current study sought to better understand the sedimentation impacts that occurred in the coral reef environment surrounding Port of Miami, to distinguish those impacts from other regional events or disturbances, and provide supplemental information on impact assessment that will inform discussions on compensatory mitigation requirements. To this end, in-water field assessments conducted after the completion of dredging and a time series analysis of tagged corals photographed pre-, during, and post-dredging, are used to discern dredging-related sedimentation impacts for the Inner Reef north. Results indicate increased sediment accumulation, severe in certain times and places, and an associated biological response (e.g., higher prevalence of partial mortality of corals) extended up to 700 m from the channel, whereas project-associated monitoring was limited to 50 m from the channel. These results can contribute to more realistic prediction of areas of indirect effect from dredging projects needed to accurately evaluate proposed projects and design appropriate compliance monitoring. Dredging projects near valuable and sensitive habitats subject to local and global stressors require monitoring methods capable of discerning non-dredging related impacts and adaptive management to ensure predicted and unpredicted project-related impacts are quantified. Anticipated increasing frequency and intensity of seasonal warming stress also suggests that manageable- but- unavoidable local stressors such as dredging should be partitioned from such seasonal thermal stress events.

Water samples were collected at several wastewater treatment plants in southeast Florida, and water and sediment samples were collected along and around one outfall pipe, as well as along several transects extending both north and south of the respective outfall outlet. Two sets of samples were collected to address potential seasonal differences, including 38 in the wet season (June 2018) and 42 in the dry season (March 2019). Samples were screened for the presence/absence of 15 select antibiotic resistance gene targets using the polymerase chain reaction. A contrast between seasons was found, with a higher frequency of detections occurring in the wet season and fewer during the dry season. These data illustrate an anthropogenic influence on offshore microbial genetics and seasonal flux regarding associated health risks to recreational users and the regional ecosystem.

Three types of benthic artificial reef units were tested by the North Carolina Division of Marine Fisheries Artificial Reef Program: steel cubes, fiberglass‐covered plastic domes, and concrete pipes. Evaluations were conducted in 1990 and 1991 at two sites in Onslow Bay, North Carolina. Reef materials were compared at the deep site (≥15 m) by quantifying stability, durability, target fish attraction, and cost per unit surface area. Assessment at the shallow site (<15 m) included only stability, durability, and cost per unit surface area. Cubes and domes were stable in shallow (<15 m) waters. Pipes and domes were stable and cubes were unstable in deep waters (≥15 m). Pipes were evaluated only at the deep site, The only structural damage observed was to two domes which were crushed during deployment. Acceptable postdeployment durability was observed for all three materials through 2 years of monitoring. Relative abundance and species richness for target fishes were assessed at the deep site and were similar for the three materials tested. Over a 2‐year period, target fishes were visually censused 125 times on the three materials, and 13 target species or groups of target fishes were observed. The only significant difference in relative abundance between materials was for gag Mycteroperca microlepis at pipes versus domes (P = 0.0001) and at pipes versus cubes (P = 0.0087). A significant decline in relative abundance of black sea bass Centropristis striata between years at pipes (P = 0.023) probably resulted from high fishing mortality. Cost per unit surface area was compared among the three materials. Pipes cost US$15.97/m2; cubes, $32.07/m2; and domes, $30.13/m2. These prices included delivery to Morehead City, North Carolina, and all assembly and deployment costs. Pipes and domes were deemed acceptable materials based on target fish attraction, stability, and durability. Cubes were unacceptable as tested, because of stability problems in deep water. Pipes were recommended for construction of low profile benthic artificial reefs off North Carolina.

The federal channel at Port of Miami, Florida, USA, was dredged between late 2013 and early 2015, to widen and deepen the channel. While the precise effects of the dredging on surrounding coral reefs are not well quantified, previously published remote sensing analyses, as well as agency and anecdotal reports suggest the most severe and largest area of sedimentation occurred on a coral reef feature referred to as the Inner Reef, particularly in the sector north of the channel. A regional warm-water mass bleaching event followed by a coral disease outbreak during this same time frame confounded the assessment of dredging-related impacts to coral reefs adjacent to the federal channel. Inwater field assessments conducted after the completion of dredging and a time series analysis of tagged corals photographed pre-, during, and post-dredging, are used to discern dredging-related sedimentation impacts for the Inner Reef north. Results indicate increased sediment accumulation, severe in certain times and places, and an associated biological response, including significantly greater proportion of live coral tissue loss, occurred within coral reef sites located closer to the channel. Dredging projects near valuable and sensitive habitats subject to local and global stressors require monitoring methods capable of discerning non-dredging related impacts and adaptive management to ensure predicted and unpredicted project-related impacts are quantified. Anticipated increasing frequency and intensity of warming stress also suggests that manageable-butunavoidable local stressors such as dredging should be partitioned from the warmest times of year.