Tobey H. Curtis

• PhD
• Fishery Management Specialist at National Marine Fisheries Service

While significant progress has been made to characterize life history patterns, movement ecology, and regional estimates of abundance of white sharks (Carcharodon carcharias) in the Western North Atlantic (WNA), patterns of spatial distribution remain relatively unknown in the northern Gulf of Maine. In this study, we utilize data collected from mu...

The elasmobranch fishes, both the sharks and rays, which inhabit the underwater environment, display breaching behaviors consisting of their sudden propulsion out of the water and into the air. They then land on top of the sea surface, displacing water upon contact. At other times, they do not completely clear the water, but partly so, performing a...

Seasonal variability in environmental conditions is a strong determinant of animal migrations, but warming temperatures associated with climate change are anticipated to alter this phenomenon with unknown consequences. We used a 40‐year fishery‐independent survey to assess how a changing climate has altered the migration timing, duration and first‐...

Basking sharks (Cetorhinus maximus) seasonally aggregate in coastal surface waters of the North Atlantic, providing opportunities for visual observation. While putative courtship displays have been observed, actual copulation has not been documented. Here we examine video collected by an unmanned aerial vehicle (“drone”) of novel behavioral interac...

This DMP outlines a comprehensive approach to handling diverse data types, including 3D model data, force transducer data, and digital high-speed imagery. Data formats such as STL, Matlab, Excel, AVI, MOV, JPG, and TIFF will be utilized. The plan emphasizes retaining data for at least five years post-award or public release, with storage on mirrore...

The Northwest Atlantic Ocean and Gulf of Mexico are among the fastest warming ocean regions, a trend that is expected to continue through this century with far-reaching implications for marine ecosystems. We examine the distribution of 12 highly migratory top predator species using predictive models and project expected habitat changes using downsc...

Species distribution models (SDMs) are becoming an important tool for marine conservation and management. Yet while there is an increasing diversity and volume of marine biodiversity data for training SDMs, little practical guidance is available on how to leverage distinct data types to build robust models. We explored the effect of different data...

Species distribution models (SDMs) are becoming an important tool for marine conservation and management. Yet while there is an increasing diversity and volume of marine biodiversity data for training SDMs, little practical guidance is available on how to leverage distinct data types to build robust models. We explored the effect of different data...

The distribution of marine species is changing as a direct result of climate change. Large pelagic highly migratory species (HMS), like tunas, billfishes, and sharks, are particularly sensitive to environmental change due to their migratory nature and use of large‐scale ocean features. These temporal and spatial shifts are likely reflected in the A...

Although portions of the Indian River Lagoon (IRL), Florida (USA), serve as essential fish habitat for US Atlantic coast bull sharks Carcharhinus leucas , past studies were short-term (days to months) and encompassed only small parts of this expansive estuarine system. In this study, 29 immature bull sharks were tracked in the IRL between Port St....

Knowledge of the three-dimensional movement patterns of elasmobranchs is vital to understand their ecological roles and exposure to anthropogenic pressures. To date, comparative studies among species at global scales have mostly focused on horizontal movements. Our study addresses the knowledge gap of vertical movements by compiling the first globa...

We conducted an interdisciplinary review of available information (i.e., genetics, life-history, and movement) to evaluate the stock structure of a previously targeted shark species, the porbeagle (Lamna nasus), in the North Atlantic. Most available information supports the conclusion that porbeagle consist of a single genetic population in the Nor...

Despite recent increases in the number of studies that have focused on the movements and habitat use of juvenile and adult white sharks (Carcharodon carcharias) in the Northwest Atlantic Ocean, there is comparatively little information on the movements of young-of-the-year (YOY) white sharks, particularly in the overwinter season. Simultaneous sate...

Spatial management for highly migratory species (HMS) is difficult due to many species’ mobile habits and the dynamic nature of oceanic habitats. Current static spatial management areas for fisheries in the United States have been in place for extended periods of time with limited data collection inside the areas, making any analysis of their effic...

States in the Northeast United States have the ambitious goal of producing more than 22 GW of offshore wind energy in the coming decades. The infrastructure associated with offshore wind energy development is expected to modify marine habitats and potentially alter the ecosystem services. Species distribution models were constructed for a group of...

As highly mobile predators with extensive home ranges, some shark species often utilize a continuum of habitats across the continental shelf ranging from the surf zone to the open ocean. For many species, these cross-shelf distributions can change depending on ontogeny or seasonal conditions. Recent research has confirmed a white shark (Carcharodon...

Thorny skate (Amblyraja radiata) have experienced decreasing abundance and range contraction in the Gulf of Maine (GOM) in recent decades. To better understand the extent to which population structure, environmental conditions, and movement ecology may play a role in these disruptions, 128 “mark-report” pop-up satellite tags (mrPATs) and 2195 conve...

Highly mobile species can be challenging for fisheries management and conservation due to large home ranges combined with dependence on discrete habitat areas where they can be easily targeted or vulnerable to anthropogenic disturbances. Management of the Dusky Shark Carcharhinus obscurus in the northwest Atlantic Ocean has been particularly challe...

The Lemon Shark Negaprion brevirostris is a large coastal shark that commonly occurs in the shallow nearshore waters of the tropical western Atlantic Ocean. There are conservation concerns for this species due to fisheries exploitation, low productivity, anthropogenic disturbance at nursery sites, and the depleted status of other large coastal shar...

Utilization of pop-up satellite archival transmitting tags to evaluate thorny skate (Amblyraja radiata) discard mortality in the Gulf of Maine groundfish bottom trawl fishery. Thorny skate (Amblyraja radiata) remain one of the most overfished species in the Gulf of Maine (GOM) despite being designated as a prohibited (zero-possession, mandatory rel...

Thorny skate (Amblyraja radiata) remain one of the most overfished species in the Gulf of Maine (GOM) despite being designated as a prohibited (zero-possession, mandatory release) species by the New England Fishery Management Council in 2003. To better understand the extent to which discard mortality (DM) occurring after incidental capture in the G...

White sharks, Carcharodon carcharias, are often described as elusive, with little information available due to the logistical difficulties of studying large marine predators that make long-distance migrations across ocean basins. Increased understanding of aggregation patterns, combined with recent advances in technology have, however, facilitated...

In recent years, white sharks (Carcharodon carcharias) have become more accessible to researchers off the northeastern U.S. as feeding aggregation sites have emerged and the population has increased. However, there has been limited research on young-of-the-year (YOY) sharks relative to older age classes in this region. Previous research indicated t...

Cetorhinus maximus aggregations recorded during extensive aerial survey efforts off the north-eastern United States between 1980 and 2013 included aggregations centring on sightings with group sizes of at least 30 individuals. These aggregations occurred in summer and autumn months and included aggregation sizes of up to 1398 individuals, the large...

Female spiny dogfish experienced high fishing pressure on the US east coast during the 1990’s. This led to a skewed population sex-ratio of 7 males per female which later declined to 4:1 as the stock was rebuilt. The current fishery still targets mature females, resulting in artificially high abundances of male spiny dogfish. Members of the fishing...

Final Report to National Marine Fisheries Service, Office of Protected Resources. 56 pp.

The skate (Rajidae) fishery off of the northeastern United States is managed as a stock complex of seven species. However, landings have not been reliably reported by species, hindering stock assessments and effective species-level management. This study was designed to characterize regional and interannual variation in the species composition of l...

When identifying potential trophic cascades, it is important to clearly establish the trophic linkages between predators and prey with respect to temporal abundance, demographics, distribution, and diet. In the northwest Atlantic Ocean, the depletion of large coastal sharks was thought to trigger a trophic cascade whereby predation release resulted...

Climate change and decadal variability are impacting marine fish and invertebrate species worldwide and these impacts will continue for the foreseeable future. Quantitative approaches have been developed to examine climate impacts on productivity, abundance, and distribution of various marine fish and invertebrate species. However, it is difficult...

Sensitivity Attributes. (PDF)

Climate exposure scoring. (PDF)

Climate Vulnerability and Distribution Change Potential. (PDF)

Climate Exposure Maps. (PDF)

Directional Effect Results. (CSV)

Species Narratives. (PDF)

Climate Model Uncertainty. (PDF)

Ocean Currents Exposure. (PDF)

Sea-level Rise Exposure. (PDF)

Data Quality. (PDF)

MDS Ordination of Sensitivity Attributes. (PDF)

Vulnerability Results. (CSV)

Assessment Results. (PDF)

Methodology Evaluation. (PDF)

Background: Satellite-based oceanographic data products are a valuable source of information on potential resource availability for marine species. Satellite oceanography data may be particularly useful in biotelemetry studies on marine species that feed at low trophic levels, such as zooplanktivorous whales, sharks, and rays. The basking shark, Ce...

Despite recent advances in field research on white sharks (Carcharodon carcharias) in several regions around the world, opportunistic capture and sighting records remain the primary source of information on this species in the northwest Atlantic Ocean (NWA). Previous studies using limited datasets have suggested a precipitous decline in the abundan...

Abstract Despite recent advances in field research on white sharks (Carcharodon carcharias) in several regions around the world, opportunistic capture and sighting records remain the primary source of information on this species in the northwest Atlantic Ocean (NWA). Previous studies using limited datasets have suggested a precipitous decline in th...

Bull Sharks Carcharhinus leucas in the Indian River Lagoon, Florida, have been documented to frequently occur in human‐altered habitats, including dredged creeks and channels, boat marinas, and power plant outfalls. The purpose of this study was to examine the short‐term movements of age‐0 and juvenile Bull Sharks to quantify the extent to which th...

Top-down versus bottom-up control of marine ecosystems has been debated for decades. Mechanisms driving mortality and energy flow are often system dependent and difficult to distinguish, especially in large systems with complex trophic webs. Large sharks have long been described as “apex predators” that assert top-down influences on ecosystems, tho...

There are two traditional fisheries for skates in the Northeast U.S.: A skate “wing” fishery which harvests large skate pectoral fins for domestic and foreign food markets, and a skate bait fishery which harvests small whole skates to supply bait to the region’s lobster fishery. The New England Fishery Management Council and NOAA Fisheries Service...

Many coastal shark species use shallow estuarine regions as nursery habitat, but there are considerable gaps in our understanding of the seasonal distribution and habitat use patterns of sharks within these systems. We compiled all available sampling data from the Indian River Lagoon (IRL) along Florida's central Atlantic coast to examine the distr...

Breaching is a behavior observed in numerous marine vertebrate species, and is typically associated with feeding, predator avoidance, parasite removal, or signaling. Few shark species have been documented to display natural breaching behavior unassociated with hook and line capture. We describe observations of breaching by juvenile bull sharks, Car...

The U.S. Atlantic coast and Gulf of Mexico commercial shark fisheries have greatly expanded over the last 30 years, yet fishery managers still lack much of the key information required to accurately assess many shark stocks. Fishery observer programs are one tool that can be utilized to acquire this information. The Commercial Shark Fishery Observe...

Distribution and habitat use of the bull shark (Carcharhinus leucas) were examined using fishery-independent sampling data, tagging, and ultrasonic telemetry to assess the potential role of the Indian River Lagoon (IRL) as a nursery area for this species. Fishery-independent sampling data were compiled and synthesized to examine patterns of seasona...

Scavenging of marine mammal carcasses is thought to be an important part of the diet of white sharks (Carcharodon carcharias), though scientific observations of this behavior are rare. A detailed analysis of this feeding behavior has not been previously reported, nor has it been compared with the documented predatory feeding habits of this species....

Unprovoked attacks by sharks on humans are exceptionally rare phenomena. Sharks typically have two motivations, feeding or defense, that result in attacks on humans. Three species, the bull, tiger, and white sharks, are responsible for the majority of attacks on humans. These predominantly feeding-motivated attacks are often the result of the shark...

The smalltooth sawfish (Pristis pectinata) and the largetooth sawfish (Pristis perotteti) are tropical marine and estuarine animals that have the northwestern termini of their Atlantic ranges in the waters of the eastern United States. We present a chronology of over 400 verified records of Pristis spp. from the U.S. between the years 1782-2002. P....

We tracked six individuals of three shark species, the shortfin mako, Isurus oxyrinchus, great white, Carcharodon carcharias, and blue, Prionace glauca, near the submarine canyon off La Jolla, southern California during the summers of 1995 and 1997. The duration of tracking ranged from 2 to 38 h per shark. The mode of travel differed in one respect...