Recreational Boating Research Articles

Microplastics in fishes of commercial and ecological importance from the Western Arabian Gulf

Microplastic particles (MPs) in the gastrointestinal tracts of nine fish species of commercial importance from different habitats (coastal, pelagic, and reef-associated) in the Saudi EEZ of the Arabian Gulf were quantified and classified. A total of eight MPs were retrieved from a total of 140 individual fish examined, with an average of 0.057 ± 0.019 microplastic items per fish (excluding possible plastic fibers). On average, 5.71%, of the fish dissected contained MPs, ranging from 5 to 15% of individual fish examined containing MPs among species (Siganus canaliculatus and Rastrelliger kanagurta, respectively). Ingested plastic consisted primarily of fishing threads (1.04 ± 0.06 mm), followed by fragments (1.16 ± 0.11 mm). It is likely that the fibers, originated from the fisheries, recreational boating, laundry, domestic wastewater, and other human activities, which is also widespread and abundant (found in 58.58% of the fish studied). Polyethylene (PE) and polypropylene (PP) were identified as the most abundant polymers ingested by the fishes. There was no significant difference (p < 0.05) between the presence of microplastic in fish depending on their habitat. The prevalence of MPs is relatively low compared to those in other regions, despite the massive industrialization of the Saudi Arabian Gulf.

Personal watercraft (PWC) injury hazards – analyses, technical advancements, and continuing safety challenges

ABSTRACTPWCs are sporty recreational boats that can hold a pilot and up to 2 additional passengers. These vessels have powerful engines driving an internal impeller that forces water through a steerable jet nozzle. This pressurized water provides thrust used for both propulsion and steering. Three-person PWCs can have 200 hp engines, and can speed across the water at 60-70 mph. PWCs are popular throughout the country and around the world. But, since the 1970’s, there has been a history of serious injuries and fatalities involving PWC operators, passengers, and bystanders. Many such incidents have been of two principal types – a.) steering-related collisions, and b.) body cavity water intrusion injuries to passengers who fell off the back of an accelerating PWC, and suffered body orifice damages caused by exposure to the pressurized water jet. PWC manufacturers tried to address both these types of hazards via precautionary instructions and warnings alone, but casualty rates remained high. Recently, engineering changes were introduced that have enhanced PWC steering, and have resulted in improved craft safety. However, no engineering changes have addressed the pressurized water intrusion type injuries. Total reliance on warnings, and deficient aspects of those warnings, continue to negatively impact PWC safety.

Evaluation of interventions focused on reducing propeller scarring by recreational boaters in Florida, USA

Propeller scarring by recreational vessels is a known threat to seagrass meadows in Florida. Despite decades of awareness about the problem, there has been little meaningful progress in addressing this largely preventable stressor. We consider it preventable because it rests on human behaviors, which can be changed by education, technology, social norms, and policy. However, past attempts to address seagrass scarring have rarely been evaluated for effectiveness. Thus, very little guidance exists for natural resource managers, educators, and policy makers responsible for allocating limited resources toward effective interventions. Using a social marketing approach, we deployed two separate interventions, one education-based and the other cue-based (navigational aids) in Florida, USA. We measured boater behavior and attitudes before and after the interventions to assess the relative effectiveness of each. Navigational aids elicited a clear behavioral improvement across a broad cross-section of boaters, while minimal effects were observed for the educational intervention. However, analyses suggest the recreational boating audience can be segmented by factors such as experience level to better target educational messages in future seagrass protection efforts. These results will assist seagrass managers, educators, advocates, policy makers, and boating industry stakeholders in deploying an efficient combination of approaches to better address propeller scarring in Florida's seagrass meadows.

The Need for Unification and Harmonization in a Maritime Licensing Standard for Recreational Craft

The objective of this document is to make clear the importance of simplifying the transit of pleasure boats and their skippers safely in the European territory with the foreseeable improvement of the functioning of the internal market. In many European countries recreational skippers are required to have specific training and experience in order to demonstrate their maritime competence. These licenses for navigation allow a recreational vessel to be skippered in each national territory. One of the main objectives of these qualifications is to reduce the number of accidents in recreational boating. Generally speaking, in the European Union, as regards the requirements for the management of pleasure craft, both private and professional, the requirements are very different depending on the member state.

Boat disturbance effects on moulting common eiders Somateria mollissima

Ship and boat traffic are increasing sources of disturbance to marine wildlife. During moult, sea ducks are flightless and rely on productive and shallow feeding areas. However, this period coincides with the peak of the recreational boating season. This is the first study to investigate the escape behaviour of moulting common eiders (Somateria mollissima) to the approach of small boats. We quantified flight initiation distances (flock-to-boat distance at which an energy-demanding escape occurred), displacement distances (distance between the pre- and post-disturbance position of the flock) and the time it took flocks to return to pre-disturbance (foraging- or resting-) behaviour. Moulting common eiders showed average flight initiation distances of 177 m and displacement distances of 771 m. Displacement distances decreased with flock size, under higher wind speeds and when previous foraging habitat was shallower. Time-to-return to pre-disturbance behaviour decreased with flock size but increased with wind speed and accessibility of foraging habitat at the previous location. Most (75%) of flocks returned to pre-disturbance behaviour within 10 min after the disturbance, while three flocks kept disturbed even 45 min after the approach. Finally, flocks encountered less accessible (deeper) habitats after disturbance than before. Our results suggest that approaching boats imply considerable disturbance effects for moulting common eiders through increased locomotion costs, displacement from accessible foraging habitat and/or time lost for foraging or resting. We provide valuable information for policy makers and marine spatial planning and highlight the need for awareness among recreational boat drivers on their impact on wildlife.

Alien Invasive Species Impacts on Large Lake Ecosystems and Their Economic Value

Globalization of trade and travel has made possible the spread of alien species across the planet. Invasive species are presently considered as one of the major threats to biodiversity in many locations throughout the world. Thousands of AIS have been transported globally by a number of anthropogenically-mediated vectors, including ship-mediated vectors (e.g., ballast water, hull-fouling), recreational boating, live bait, aquarium trade, live food fish, and unauthorized introductions. Ballast water is one of the leading vectors for transporting and introducing species, both in Canada and around the world, and is responsible for the transport of at least one third of all documented marine invasions. Since invasive species have no regard for political boundaries, efforts to prevent invasions need to be interjurisdictional. Given, also that invasive species often travel as contaminants of trade transfers, for example, in the ballast tanks of ships, reducing the spread of invasive species via this pathway would either require constraints on where ships travel, or the installation onto all ships of expensive ballast treatment technology, thereby increasing the cost of shipped goods. As such cost benefit analysis involves trade-offs with other activities, complicating decisions about how impacts can best be managed.

Assessing stakeholder perceptions of landscape and place in the context of a major river intervention: a call for their inclusion in adaptive management

AbstractAdaptive management strategies are required to manage multi-actor and multifunctional river landscapes. Such strategies need to be inclusive of perspectives of different stakeholders. We present a case study of a pilot engineering project in the Dutch river Waal, which drastically changed the appearance of the river landscape. We study perceptions of four stakeholder groups (residents, recreational anglers, recreational boaters and shipping professionals) regarding the impacts of this intervention on landscape values, including aesthetics, naturalness, biodiversity, flood safety and accessibility. Results show that stakeholders differ in which functions of the river landscape they find important and how they perceive the longitudinal dams to influence the landscape. They also differ in levels of place attachment and trust in the responsible authority. Shipping professionals stand out for their more negative evaluations of the dams compared to the other stakeholders, while especially residents demonstrate high levels of place identity and connection with nature. Residents also feel that the dams are improving flood risk safety in the area, and they positively evaluate knowledge and skills of Dutch water managers. These results provide water managers with much needed insights into landscape functions valued by different stakeholder groups and those perceived as most endangered by landscape interventions.

Underwater noise recognition of marine vessels passages: two case studies using hidden Markov models

Abstract Passive acoustic monitoring (PAM) is emerging as a cost-effective non-intrusive method to monitor the health and biodiversity of marine habitats, including the impacts of anthropogenic noise on marine organisms. When long PAM recordings are to be analysed, automatic recognition and identification processes are invaluable tools to extract the relevant information. We propose a pattern recognition methodology based on hidden Markov models (HMMs) for the detection and recognition of acoustic signals from marine vessels passages and test it in two different regions, the Tagus estuary in Portugal and the Öresund strait in the Baltic Sea. Results show that the combination of HMMs with PAM provides a powerful tool to monitor the presence of marine vessels and discriminate different vessels such as small boats, ferries, and large ships. Improvements to enhance the capability to discriminate different types of small recreational boats are discussed.

Recreational vessels without Automatic Identification System (AIS) dominate anthropogenic noise contributions to a shallow water soundscape

Recreational boating is an increasing activity in coastal areas and its spatiotemporal overlap with key habitats of marine species pose a risk for negative noise impacts. Yet, recreational vessels are currently unaccounted for in vessel noise models using Automatic Identification System (AIS) data. Here we conduct a case study investigating noise contributions from vessels with and without AIS (non-AIS) in a shallow coastal area within the Inner Danish waters. By tracking vessels with theodolite and AIS, while recording ambient noise levels, we find that non-AIS vessels have a higher occurrence (83%) than AIS vessels, and that motorised recreational vessels can elevate third-octave band noise centred at 0.125, 2 and 16 kHz by 47–51 dB. Accordingly, these vessels dominated the soundscape in the study site due to their high numbers, high speeds and proximity to the coast. Furthermore, recreational vessels caused 49–85% of noise events potentially eliciting behavioural responses in harbour porpoises (AIS vessels caused 5–24%). We therefore conclude that AIS data would poorly predict vessel noise pollution and its impacts in this and other similar marine environments. We suggest to improve vessel noise models and impact assessments by requiring that faster and more powerful recreational vessels carry AIS-transmitters.

Behavioural and morphological changes in fish exposed to ecologically relevant boat noises

There is increasing concern about the effect of underwater noise on fish due to rising levels of anthropogenic noise. We performed experiments on the black bullhead (Ameiurus melas), a species with known hearing specializations and located within the Laurentian Great Lakes where there is considerable commercial and recreational boat traffic. We tested and compared physiology (baseline cortisol), behaviour (activity, sheltering), and morphology (ciliary bundles of hair cells) of bullhead to boat noise. At 140 dB re 1 μPa (−54.84 dB re 1 m·s−2), we saw clear behavioural effects in terms of both activity and sheltering levels despite no obvious morphological or physiological stress. Following both short- and long-period acute exposure to higher — but environmentally relevant — noise levels, bullhead were less active and sheltered more and also exhibited a decrease in ciliary bundles. These results suggest that there are sublethal effects of anthropogenic noise on fish behaviour and ciliary bundles, which may have direct implications on population health. Moreover, commonly used metrics such as stress hormones may not always offer the most relevant biomarker of the response to anthropogenic boat noise.

Alien species spreading via biofouling on recreational vessels in the Mediterranean Sea

AbstractDespite the Mediterranean being both a hotspot for recreational boating and for non‐indigenous species (NIS), no data currently exists on the recreational boating sector's contribution to the spread of NIS in this Sea.To improve the basis for management decisions, a wide‐scale sampling study on the biofouling communities of recreational vessels and marinas was undertaken. Specifically, we surveyed over 600 boat owners and sampled the same boat hulls for NIS in 25 marinas across the Mediterranean, from France to Cyprus, to determine which factors (i.e. boat characteristics, travel behaviour, home marina) are associated with higher NIS richness on boat hulls.Among the surveyed boats, we found recreational vessels to travel considerably, averaging 67 travel days and 7.5 visited marinas per annum. This results in a high potential for spreading NIS, especially as 71% of sampled vessels host at least one (and up to 11) NIS. Boats with high NIS richness strongly correlate with home marinas with high NIS richness. Over half of the vessels were carriers of NIS which were not yet present in the marinas they were visiting. The presence of biofouling in niche areas of the hull (i.e. in the cavities and metallic parts) emerges as the best predictor for NIS richness on boats, along with longer times since their last cleaning and antifouling applications. Interestingly, colonization of NIS occurred rapidly, even on boats that had recently had their hulls cleaned professionally.Synthesis and applications. We demonstrate that recreational boating has a very high capacity for the spread of non‐indigenous species (NIS) in the Mediterranean, due to both high NIS richness on boats and extensive travel. To counteract the spread of NIS, routine monitoring for new NIS needs to be established for both marinas and vessels, along with frequent pontoon cleaning. Additionally, policy should require preliminary screenings for incoming vessels from new countries, especially those emanating from high‐risk marinas. The niche areas of the boat hulls should be checked first for biofouling, which was the best predictor for NIS richness since they often go overlooked with in‐water cleanings are rarely have antifouling applied to them.

Defining boat wake impacts on shoreline stability toward management and policy solutions

Coastal economies are often supported by activities that rely on commercial or recreational vessels to move people or goods, such as shipping, transportation, cruising, and fishing. Unintentionally, frequent or intense vessel traffic can contribute to erosion of coastlines; this can be particularly evident in sheltered systems where shoreline erosion should be minimal in the absence of boat waves. We reviewed the state of the science of known effects of boat waves on shoreline stability, examined data on erosion, turbidity, and shoreline armoring patterns for evidence of a response to boat waves in Chesapeake Bay, and reviewed existing management and policy actions in Chesapeake Bay and nearby states to make recommendations for actions to minimize boat wake impacts. In the literature, as well as in our analyses, boat wake energy may be linked to elevated turbidity and shoreline erosion, particularly in narrow waterways. In Chesapeake Bay, three lines of evidence suggest boat waves are contributing to shoreline erosion and poor water clarity in some Bay creeks and tributaries: 1) nearshore turbidity was elevated in many waterways during periods of expected high boating activity, 2) armoring was placed along about a quarter of the low energy shorelines of three examined tidal creeks that are exposed to relatively high boating pressure, and 3) 15% of the shorelines we examined throughout the Bay (9000 km) are low energy shorelines that are experiencing high erosion (≥0.3 m/yr) that cannot be attributed to wind wave energy. Still, there remain significant data gaps that preclude the determination of the overall contribution of boat waves to shoreline erosion throughout the Bay, notably, shoreline erosion data in low energy waterways, recreational boating traffic patterns, and nearshore bathymetry. Interim protective measures can be (and have been) applied in high risk waterways, such as small, low energy waterways that have high recreational boating activity, to help reduce shoreline erosion. Policy options used in Bay states and elsewhere include setbacks from the shore, wake restrictions, and speed restrictions; other more restrictive policies may include prohibition on boats of a certain size or limiting the number of passages. Finally, a systems-approach to boat wake impact management using uniform boat wake policies is likely to be the most effective for consistent shoreline protection.

Passive acoustic monitoring shows no effect of anthropogenic noise on acoustic communication in the invasive round goby (Neogobius melanostomus)

Abstract Passive acoustic monitoring (PAM) can be a powerful tool to survey populations of soniferous species in natural settings. Using PAM allows monitoring of behaviour and activity unobtrusively to get a more accurate assessment of behavioural responses than traditional techniques. The use of PAM can also be beneficial for behaviourally cryptic species or other taxa that might be missed by more traditional sampling methods. To quantify seasonality of reproduction in an aquatic invasive species and to assess possible interactions between both abiotic and biotic noise and acoustic ecology, we deployed multiple hydrophones to fully characterise the acoustic behaviour of round goby (Neogobius melanostomus), a highly invasive species. We also aimed to quantify levels of anthropogenic noise around the goby communities. We tested correlations of round goby calling rates with overall noise levels and the presence of boat traffic as direct tests of the hypothesised role of noise on natural acoustic behaviour of fish. Round goby showed a clear diel patterning of calling behaviour, with the highest activity during the night and ceasing at midday; supporting the importance of acoustic—as opposed to visual—signalling for mate attraction. Calls also allowed us to pinpoint spawning areas for possible remediation. We saw no correlation between measures of background noise and calling behaviour or presence of boats and calling, suggesting that increased levels of noise have no effect on the natural calling behaviour of this species. Passive acoustic monitoring of round goby calling behaviour is a promising technique for those interested in remediation of this highly invasive species, as it can be difficult to quantify population levels by more conventional means. The lack of noise effects we see suggests that noise from recreational boats does not disrupt signalling in this species with limited hearing range, although more investigation is needed to ascertain whether noise could be a stressor in other contexts.

Assessing behavioural and social responses to an eco-mooring trial for Zostera marina conservation management in Torbay, Southwest England

Seagrass beds are critically important habitats delivering a range of ecosystem service benefits that support human wellbeing. They are, however, declining globally at an unprecedented rate. The damaging effects on Zostera marina (Common Eelgrass) seagrass beds in UK waters from mechanical recreational boating activities, namely anchoring and traditional swing mooring scour, suggest that measures of implementing management to mitigate human impacts need prioritising. Eco-moorings, a design that reduces the abrasion pressure of anchoring and mooring on the seabed, are such a mitigation method. In the UK, limited test sites and a lack of social acceptance of the technology compounds the limited uptake of eco-moorings to date. To advance the evidence base, this study focusses on a bespoke eco-mooring design deployed in 2017 to protect seagrass beds within a popular anchorage in Southwest England. We assess the behavioural and social responses of recreational boaters to the trial eco-mooring through 1) mapping of boating activity pre- and post-deployment and 2) structured questionnaires both on-site and online to local and national audiences respectively. Results of mapped boating activity demonstrated a shoreward distribution shift of anchoring away from the deployed eco-mooring, with 45.4% of all anchoring vessels directly within or within a range of potential influence of the seagrass bed. Through the deployment of the eco-mooring (where no mooring previously existed), an estimated additional 20% of anchoring pressure was alleviated from the seagrass bed. A total of 89.6% of on-site respondents reacted positively to the prospect of further eco-moorings being deployed locally. When questioned, 74.6% of on-site and 82.8% of online respondents demonstrated a preference for the physical action of mooring a vessel over anchoring. This suggests that implementation of eco-moorings in seagrass-dense regions could successfully alleviate anchor damage, especially where over half of respondents indicated an awareness of seagrass presence prior to anchoring their vessel and/or hesitance to cease visiting preferential anchoring sites (sheltered bays). This study recommends targeting conservation guidance at the powerboat community, the dominant group anchoring/mooring in the study area and identified as not currently engaged in seagrass education campaigns. It is proposed that management introduce incentives such as free of charge eco-moorings and/or anchoring charges in Marine Protected Areas/Voluntary No Anchor Zones to conserve and recover seagrass and other sensitive seabed habitats nationally.

Promising Practices for Alternatives Assessment: Lessons from a Case Study of Copper-Free Antifouling Coatings.

Alternatives assessment (AA) is intended to identify safer and more sustainable approaches for managing chemicals used in industrial applications and consumer products and to avoid the adoption of regrettable substitutions. In the United States, the state of Washington prescribes a science-based approach for conducting an AA that meets regulatory requirements. This paper provides an overview of the approach, based on the Interstate Chemicals Clearinghouse (IC2) AA Guide, and illustrates its application to the examination of suitable alternatives to Cu-based antifouling coatings commonly used for recreational boats in the Pacific Northwest. Legislation has been passed in Washington State that will ban the use of certain Cu-based products in both freshwater and marine environments. The AA approach was used to identify and evaluate several alternatives to Cu-based antifouling boat paint products. Five promising practices that AA practitioners should consider when using the IC2 AA Guide in similar assessments of alternatives to industrial practices and consumer products include actively engaging stakeholders, enhancing the decision framework using a selection guide approach, scoping alternatives broadly, optimizing ingredient transparency, and identifying data gaps that could interfere with substitution efforts. The role AA plays in driving consumer product and similar technology innovations and its implications for the future are discussed. Environ Assess Manag 2019;00:1-13. © 2019 SETAC.

Raster charting products in an ENC-first era

Abstract. Nautical charts are an essential tool for marine navigation. Despite the introduction of global positioning systems (GPS) and electronic navigational tools that present navigation data in a vector format on a display, paper charts are still the preferred choice for many mariners. Interestingly, since the introduction of Electronic Navigation Charts (ENCs) more than thirty years ago, the size of commercial vessels has increased more than four-fold, modern navigational systems have become more sophisticated, and recreational boaters have joined professional mariners in using electronic chart displays. Marine and coastal users of all types are expecting higher resolution and more precision in location of the charted features, and shorter update times for data sources to be published on the chart. With NOAA’s new plan to “standardized, consistent gridded framework” that is optimized for digital displays, it leaves the future of paper charts in question. In order to support a raster-based maintenance system, it is now possible to translate encoding attributes of vector objects into standardized chart symbols and labels. Thus, simplifying workflow processes for paper and raster chart production. This paper discusses NOAA Marine Chart Division’s raster workflow in an ENC-first production line. The paper reviews the benefits of the new desktop tools and web-services for providing chart updates in a timely manner for a broader community.

Hydrodynamic analysis and improvement of pontoon boats

This study is related to the design features of pontoon boats that enjoy an increasing market share in global recreational boat industry. In this investigation, a representative pontoon boat with three cylindrical buoyancy elements was taken as the model to be studied. Afterwards, the buoyancy elements were improved to optimize hydrodynamic properties using a computational fluid dynamics package. The objective functions were the total hydrodynamic resistance of the boat and the distribution of the turbulence viscosity and total pressure on the hulls. By means of the obtained results, the powering requirements were estimated both for a service speed and for a maximum speed as well as findings were discussed.

Concurrent Western Australian telephone surveys highlight the advantages of sampling from a registry of recreational fishers

Abstract Surveys play an integral role in providing reliable recreational fishing information for the sustainable management of fisheries resources. The selection of a representative sample is an important and often challenging part of designing surveys. Here we compare concurrent telephone surveys conducted in 2016 and 2017 using a telephone directory (White Pages®, WP) and a Recreational Boat Fishing Licence (RBFL) as sampling frames. Information on boat- and shore-based recreational fishing was collected from both surveys. The response rates for the RBFL surveys were more than double those from the WP surveys. The RBFL surveys identified more respondents who had recreationally fished in the previous 12 months compared to the WP surveys. Fishing activity differed markedly between fishers in the WP and RBFL surveys; however, characteristics were consistent for boat-based fishers sampled from the two types of surveys. The high levels of sample loss observed in the WP surveys suggest that other general population lists may provide greater coverage of shore-based fishers. We recommend testing the demographic and behavioural characteristics of recreational fishers sampled in offsite surveys against benchmark data to assist in assessing whether or not the characteristics of the sample are representative of the target population.

Boating-related drowning in Australia: Epidemiology, risk factors and the regulatory environment

Objective: Recreational boating is a popular pastime in many high income countries, and is a leading activity prior to drowning. This study reports on unintentional fatal drowning associated with boating-related incidents in Australia. Methods: A total population, retrospective, cross sectional design examined all boating-related unintentional drowning deaths between July 1, 2005 and June 30, 2015. Variables examined included age, sex, location of drowning incident, vessel type, activity, presence of alcohol/drugs, and lifejacket wear. Relative risk (with a 95% confidence interval) was calculated using fatal drowning rates per 100,000 population and rates per 100,000 registered vessels. Chi square analysis and non-parametric tests for significance were applied. Statistical significance was deemed p < .05. Results: A total of 415 people drowned while boating during the study period, 91.8% male and 35.7% aged between 25 and 44 years. Men were 10 times more likely to drown when boating than females (RR = 10.64 CI:7.55–14.97). Over one-quarter (28.7%) of incidents involved alcohol, in 30.6% drugs were identified (31.3% were illegal) and 90.4% were not wearing a lifejacket. Children were more at risk of drowning on a houseboat than adults (RR = 7.13; CI:1.61–31.61). Females were more likely to drown than males when using a personal watercraft (RR = 10.53; CI:2.75–40.33). Conclusion: Boaters may be taking unnecessary risks by disregarding safety regulations, such as not wearing lifejackets and substance use (such as alcohol and illegal drugs). Boating in remote locations presents a high risk of drowning. While safety regulations are in place, enforcement and behavior change remain challenges. Practical application: Findings support recommendations for increased enforcement of alcohol-related regulations and introducing drug-testing for boaters. Consistency of boating safety regulations, especially around lifejacket wear, is recommended to influence behavior change. The effectiveness of current lifejacket regulations need to be critically evaluated in the context of increasing wear rates for adults and children.

Linking Use of Ship Channels by West Indian Manatees (Trichechus manatus) to Seasonal Migration and Habitat Use

Research on marine mammal occurrence in ship channels often focuses on large cetaceans in offshore shipping routes, while nearshore research largely addresses small vessel strikes. Marine mammals, such as the West Indian manatee, that reside in or migrate through nearshore areas, have potential to travel through a wide range of channel types, encountering a greater diversity of vessels than previously recognized. We tested the extent and conditions of ship channel use by manatees along the north-central Gulf of Mexico (nGoM) coast by combining data from telemetry-tracked individuals, opportunistic citizen-sourced sightings, and environmental attributes linked to manatee movements. Manatees used both nearshore boat channels (130 and 300m wide) and open water fairways but used nearshore channels much more frequently, consistent with habitat requirements. Satellite-tracked individuals swam faster and moved more directly in all channel types, indicating use of these channels as migratory and travel corridors. Accordingly, generalized additive models revealed that manatees used channels most often during spring/early summer and fall and at temperatures coincidental with entry to and exit from the nGoM during migration. Manatees also occurred in ship channels when freshwater discharges were low, likely because timing of peak manatee occurrence in the nGoM coincides with seasonally low discharge periods. Expanding shipping activity world-wide is likely to increase interactions between marine mammals and a variety of vessel types, and these effects may be particularly impactful to migratory animals like manatees that use nearshore habitats at the interface of recreational boating and commercial shipping. Linking near- and offshore ship channel use to migration and habitat use will better aid risk-assessment for vessel collision and other shipping related activities for migratory marine species globally.