Nathan Putman

Nathan Putman
LGL Ecological Research Associates

PhD

About

102
Publications
27,493
Reads
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3,463
Citations
Additional affiliations
March 2015 - February 2016
University of Miami
Position
  • PostDoc Position
June 2012 - May 2014
Oregon State University
Position
  • PostDoc Position
October 2011 - June 2012
North Carolina State University
Position
  • Distinguished Postdoctoral Fellow

Publications

Publications (102)
Article
Full-text available
Blooms and coastal inundations of pelagic Sargassum have caused major problems to coastal communities and ecosystems throughout the tropical Atlantic over the past decade. Understanding Sargassum growth, movement, and mortality is essential to being able to predict and mitigate these events. In principle, tropical cyclones that occur in this area c...
Preprint
By analyzing a time-homogeneous Markov chain constructed using trajectories of undrogued drifting buoys from the NOAA's Global Drifter Program, we find that probability density can distribute in a manner that resembles very closely the recently observed recurrent belt of high Sargassum density in the tropical Atlantic between 5-10oN coined the Grea...
Technical Report
EXECUTIVE SUMMARY The National Oceanic and Atmospheric Administration (NOAA) National Marine Fisheries Service (NMFS) is increasingly urging an Ecosystem Based Fisheries Management (EBFM) approach that considers fisheries within their holistic ecosystem context and seeks to optimize benefits among a diverse set of societal goals. Fishery Ecosystem...
Article
Full-text available
Pacific salmon are recognized for their amazing abilities to memorize their natal river information during a short-distance downstream migration, carry out a long-distance feeding migration in the ocean for many years for growth, and make a precise long-distance spawning migration from oceanic feeding habitat to their natal river for reproduction....
Article
Full-text available
Offshore petroleum platforms provide habitat that is utilized by an array of reef fish that are valuable to both commercial and recreational fishers. However, thousands of offshore platforms have been decommissioned in the Gulf of Mexico over the past decade, with many of the removals being accomplished using explosive severance methods. Here, we e...
Article
Full-text available
The number of subsea cables in the marine environment is likely to grow substantially in the near future. Arrays of energy‐generating windmills or wave power generators are planned for installation in the coastal waters of many countries worldwide. The electricity generated by these and other marine energy sources will be transported to shore throu...
Article
Migration is common in marine animals,1, 2, 3, 4, 5 and use of the map-like information of Earth’s magnetic field appears to play an important role.²,6, 7, 8, 9 While sharks are iconic migrants10, 11, 12 and well known for their sensitivity to electromagnetic fields,13, 14, 15, 16, 17, 18, 19, 20 whether this ability is used for navigation is unres...
Article
‘True navigation’ indicates that animals can move toward a destination without using familiar landmarks. Migratory birds apparently achieve this by extrapolating their position from geomagnetic cues. What this ability implies about the function and representation of animals’ large-scale maps remains uncertain.
Article
Full-text available
We deployed 19 satellite tags on foraging adult leatherback turtles, including 17 females and 2 males, captured in the northeastern Gulf of Mexico in 2015, 2018, and 2019 in order to study regional distribution and movements. Prior to our study, limited data were available from leatherbacks foraging in the Gulf of Mexico. Tag deployment durations r...
Article
Full-text available
Pelagic Sargassum is a buoyant macroalgae that forms rafts at the ocean surface and serves as a biologically rich habitat for hundreds of diverse marine species. Since 2011, massive blooms of Sargassum have occurred in the tropical Atlantic and swept through the western tropical Atlantic, Caribbean Sea, and Gulf of Mexico. These recurring annual ev...
Article
Full-text available
Ocean circulation models are an essential tool for use in estimating the movements of drifting marine species. Across the world, hatchling sea turtle transport to the pelagic ocean is facilitated by the local currents off their natal beaches. It is difficult, if not impossible, to observe this transport reliably for any lengthy period, and, as such...
Article
Loggerhead sea turtles (Caretta caretta) nest globally on sandy beaches, with hatchlings dispersing into the open ocean. Where these juveniles go and what habitat they rely on remains a critical research question for informing conservation priorities. Here a high-resolution Earth system model is used to determine the biophysical geography of favour...
Article
Full-text available
In the Gulf of Mexico, the bulk of published studies for sea turtles have focused on northern (United States) waters where economic resources are centered, with fewer studies in the southern portion of the basin, resulting in significant knowledge gaps in these underrepresented areas. Similarly, publications on adult sea turtles are dominated by re...
Article
Full-text available
Drifters designed to mimic floating marine debris and small patches of pelagic Sargas- sum were satellite tracked in four regions across the North Atlantic. Though subjected to the same initial conditions at each site, the tracks of different drifters quickly diverged after deployment. We explain the clustering of drifter types using a recent Maxey...
Article
Many animals undertaking long-distance migrations use Earth’s magnetic field as a “map” to assess their position for orientation. This phenomenon been particularly well-studied in salmonids using “magnetic displacement” experiments, in which animals are presented with magnetic field conditions that are characteristic of other geographic locations....
Article
A mechanistic understanding of organismal movement provides context for existing biogeographic and ecological patterns and improves our ability to predict changing patterns in dynamic environments. Here, we examined the movement ecology of pelagic Sargassum in the northern Caribbean Sea, where major inundation events of this brown algae have become...
Poster
Full-text available
Movement characterizes life in marine ecosystems. The journal Water invites submissions to the Special Issue, "Marine Species on the Move", which aims to coalesce research on the mechanisms of marine species movement (e.g., fluid dynamics, biomechanics, physiology, sensory biology, and species interactions) and the implications of those movements (...
Preprint
Full-text available
Drifters designed to mimic floating marine debris and small patches of pelagic \emph{Sargassum} were satellite tracked in four regions across the North Atlantic. Though subjected to the same initial conditions at each site, the tracks of different drifters quickly diverged after deployment. We explain the clustering of drifter types using a recent...
Article
Full-text available
For decades, fisheries have been managed to limit the accidental capture of vulnerable species and many of these populations are now rebounding. While encouraging from a conservation perspective, as populations of protected species increase so will bycatch, triggering management actions that limit fishing. Here, we show that despite extensive regul...
Article
Shifts in the return locations of juvenile seabirds migrating from the Irish Sea to Argentina can be accurately predicted by changes in Earth’s magnetic field, suggesting that these birds rely on a geomagnetic map for navigation.
Article
Ocean circulation driving macro-algal rafting is believed to serve as an important mode of dispersal for many marine organisms, leading to predictions on population-level genetic connectivity and the directionality of effective dispersal. Here, we use genome-wide single nucleotide polymorphism data to investigate whether gene flow directionality in...
Article
Full-text available
Environmental variability can be an important factor in the population dynamics of many species. In marine systems, for instance, whether environmental conditions facilitate or impede the movements of juvenile animals to nursery habitat can have a large influence on subsequent population abundance. Both subtle differences in the position of oceanog...
Article
Full-text available
During the mass nesting of olive ridley sea turtles, Lepidochelys olivacea, thousands of adult females aggregate offshore, then emerge from the ocean together to lay their eggs along small, specific stretches of coastline. Little is known about the mechanisms that underlie synchronization of mass nesting. As a first step towards identifying environ...
Article
A variety of animals sense Earth's magnetic field and use it to guide movements over a wide range of spatial scales. Little is known, however, about the mechanisms that underlie magnetic field detection. Among teleost fish, growing evidence suggests that crystals of the mineral magnetite provide the physical basis of the magnetic sense. In this stu...
Article
Full-text available
Despite a complex management landscape and decades of overfishing, Red Snapper (Lutjanus campechanus) stocks have grown substantially in the Gulf of Mexico and restrictions on the fisheries that catch them are being loosened. This year, annual shrimping effort was allowed to increase by 21% after National Marine Fisheries Service scientists conclud...
Article
The use of "map-like" information from Earth's magnetic field for orientation has been shown in diverse taxa, but questions remain regarding the function of such maps. We used a "magnetic displacement" experiment to demonstrate that juvenile pink salmon (Oncorhynchus gorbuscha) use magnetic cues to orient. The experiment was designed to simultaneou...
Article
Full-text available
We present results from an experiment designed to better understand the mechanism by which ocean currents and winds control flotsam drift. The experiment consisted of deploying in the Florida Current and subsequent satellite tracking of specially designed drifting buoys of various sizes, buoyancies, and shapes. We explain the differences in the tra...
Article
Full-text available
Starting in 2011, coastal areas of the Caribbean Sea and tropical Atlantic Ocean began to experience extraordinary yearly accumulations of pelagic Sargassum brown alga. Historical reports place large quantities of Sargassum only in the North Atlantic (mostly in the Gulf of Mexico and the Sargasso Sea). Accumulations of Sargassum in the tropical Atl...
Conference Paper
Full-text available
From a human’s perspective, the navigational task of ocean migrants is daunting: the open sea is vast, featureless, and in constant motion. Yet, numerous species transit ocean basins with seeming ease (Gould and Gould 2012). The migratory life-cycle is common and often includes use of spatially-restricted reproductive sites, dispersal of offspring,...
Article
Full-text available
Oceanic dispersal characterizes the early juvenile life‐stages of numerous marine species of conservation concern. This early stage may be a ‘critical period’ for many species, playing an overriding role in population dynamics. Often, relatively little information is available on their distribution during this period, limiting the effectiveness of...
Article
Natural mortality rates and fecundity of Red Snapper (Lutjanus campechanus) vary substantially by age, thus age composition of catch is an important consideration when quantifying relative impacts across different fisheries. For instance, the shrimp fishery catches many, but younger, Red Snapper whereas directed commercial and recreational fisherie...
Preprint
Full-text available
We present results from an experiment designed to better understand the mechanism by which ocean currents and winds control flotsam drift. The experiment consisted in deploying in the Florida Current and subsequently satellite tracking specially designed drifting buoys of varied sizes, buoyancies, and shapes. We explain the differences in the traje...
Article
Full-text available
In coastal waters around the world, the dominant primary producers are benthic macrophytes, including seagrasses and macroalgae, that provide habitat structure and food for diverse and abundant biological communities and drive ecosystem processes. Seagrass meadows and macroalgal forests play key roles for coastal societies, contributing to fishery...
Book
Full-text available
SWOT Report XIV features an up-to-date, comprehensive map of sea turtle distribution in the Mediterranean, a picture of loggerhead movements in the Atlantic, and expert answers to the most frequently asked questions about sea turtles. Other articles explore the effects of red tides on turtles, best practices for transporting stranded turtles, and...
Article
Long-distance migrants, including Pacific salmon (Oncorhynchus spp), can use geomagnetic information to navigate. We tested the hypothesis that a "magnetic map" (i.e., an ability to extract positional information from Earth's magnetic field) also exists in a population of salmon that do not undertake oceanic migrations. This study examined juvenile...
Article
There is great diversity in the animal species that migrate, the biomechanics that propel their locomotion and the ecosystems through which they transit. This diversity, however, is unified by a common condition: the relative suitability of places changes in predictable and cyclical ways. Owing to the periodicity of environmental change (e.g., seas...
Data
Will the Southern Ocean’s relentless waves undo Antarctica’s ecological isolation? The discovery of a wayward piece of kelp and a simple numerical experiment set new expectations for the potential invasion of Earth’s most isolated continent.
Article
Will the Southern Ocean’s relentless waves undo Antarctica’s ecological isolation? The discovery of a wayward piece of kelp and a simple numerical experiment set new expectations for the potential invasion of Earth’s most isolated continent.
Article
How animals integrate different sensory information for orientation is a complex process involving interactions between a variety of internal and external factors. Due to this complexity, each component of a suite of factors is typically studied in isolation. Here, we examine how an internal factor (personality of fish) influences the response of z...
Article
Full-text available
Since 2011, beach inundation of massive amounts of pelagic Sargassum algae has occurred around the Caribbean nations and islands. Previous studies have applied satellite ocean color to determine the origins of this phenomenon. These techniques, combined with complementary approaches, suggest that, rather than blooms originating in the Caribbean, th...
Preprint
Full-text available
The Kemp's ridley (Lepidochelys kempii) is the most endangered sea turtle species. During 1966-2017, an annual count of nests (i.e., clutches of eggs laid) has served as an annual index of Kemp's ridley nesting female abundance on the Gulf of Mexico (GoM) index beach in Tamaulipas, Mexico. This index was increasing exponentially at 19% per year in...
Article
Full-text available
This paper has been published online, open access: The Kemp’s ridley (Lepidochelys kempii) is the most endangered sea turtle species. During 1966–2017, an annual count of nests (i.e., clutches of eggs laid) has served as an annual index of Kemp’s ridley nesting female abundance on the Gulf of Mexico (GoM) index beach in Tamaulipas, Mexico. This in...
Article
Ecosystem-based fisheries management (EBFM) is gaining traction worldwide, including in the Gulf of Mexico (GOM). Ecosystem models, such as applications of the Atlantis and Ecospace modeling approaches, are key tools for assisting EBFM. Patterns of spatial overlap between exploited fish species, other species of concern such as marine mammals and s...
Article
Organisms use a variety of environmental cues to orient their movements in three-dimensional space. Here, we show that the upward movement of young Chinook salmon (Oncorhynchus tshawytscha) emerging from gravel nests is influenced by the geomagnetic field. Fish in the ambient geomagnetic field travelled farther upwards through substrate than did fi...
Article
Full-text available
Aim: Long-distance dispersal (LDD) events occur rarely but play a fundamental role in shaping species biogeography. Lying at the heart of island biogeography theory, LDD relies on unusual events to facilitate colonization of new habitats and range expansion. Despite the importance of LDD, it is inherently difficult to quantify due to the rarity of...
Article
Full-text available
In the South Atlantic Ocean, few data exist regarding the dispersal of young oceanic sea turtles. We characterized the movements of laboratory-reared yearling loggerhead turtles from Brazilian rookeries using novel telemetry techniques, testing for differences in dispersal during different periods of the sea turtle hatching season that correspond t...
Article
Our recent study [1] in Current Biology used a magnetic displacement experiment and simulations in an ocean circulation model to provide evidence that young European eels possess a ‘magnetic map’ that can aid their marine migration. Our results support two major conclusions: first, young eels distinguish among magnetic fields corresponding to locat...
Article
Full-text available
Migration allows animals to track the environmental conditions that maximize growth, survival, and reproduction [1–3]. Improved understanding of the mechanisms underlying migrations allows for improved management of species and ecosystems [1–4]. For centuries, the catadromous European eel (Anguilla anguilla) has provided one of Europe’s most import...
Article
Full-text available
Kemp’s Ridley Sea Turtle (Lepidochelys kempii) conservation practices permitted by National Marine Fisheries Service (NMFS) and U.S. Fish and Wildlife Service (USFWS), under authority of the U.S. Endangered Species Act of 1973, include translocations in which eggs or turtles are taken into captivity for various reasons and intervals, and turtles ar...
Article
Full-text available
Predictions of organismal movements in a fluid require knowing the fluid’s velocity and potential contributions of the organism’s behaviour (e.g. swimming or flying). While theoretical aspects of this work are reasonably welldeveloped, field-based validation is challenging. A much-needed study recently published by Briscoe and colleagues in Proceed...
Article
Full-text available
We developed a Kemp’s ridley (Lepidochelys kempii) stock assessment model to evaluate the relative contributions of conservation efforts and other factors toward this critically endangered species’ recovery. The Kemp’s ridley demographic model developed by the Turtle Expert Working Group (TEWG) in 1998 and 2000 and updated for the binational recove...
Article
The green turtle (Chelonia mydas) foraging aggregation along the Texas coast has increased dramatically in recent years, but the source populations for these turtles have not been adequately resolved. Previous mixed stock analysis (MSA) based on 490 base pair (bp) mitochondrial control region haplotypes suggested a large Florida contribution, but w...
Article
Rheotaxis, the unconditioned orienting response to water currents, is a main component of fish behaviour. Rheotaxis is achieved using multiple sensory systems, including visual and tactile cues. Rheotactic orientation in open or low-visibility waters might also benefit from the stable frame of reference provided by the geomagnetic field, but this p...
Article
Ocean currents play an important role in the movement and distribution of organisms and for small animals it is often assumed that their movements in the ocean are determined by passive drift. Here we challenge this assumption by conducting an experiment at the scale of an entire ocean basin to test whether small (~35 cm) juvenile loggerhead sea tu...
Article
The diverse movements of animals are unified by the problem that locations that are most favorable at one particular time are not likely to be the most favorable at another. This might be due to environmental variation (e.g., diurnal or seasonal changes in temperature or food availability), or it could be intrinsic to the organism, as different lif...
Article
The full text of this paper is available from: http://www.chelonianjournals.org/doi/full/10.2744/CCB-1189.1 Its Erratum is in CHELONIAN CONSERVATION AND BIOLOGY, Volume 15, Number 2, December 2016
Article
Full-text available
Sea turtles are capable of navigating across large expanses of ocean to arrive at remote islands for nesting, but how they do so has remained enigmatic. An interesting example involves green turtles (Chelonia mydas) that nest on Ascension Island, a tiny land mass located approximately 2000 km from the turtles' foraging grounds along the coast of Br...
Article
Full-text available
We investigated the extent that the 2010 Deepwater Horizon oil spill potentially affected oceanic-stage sea turtles from populations across the Atlantic. Within an ocean-circulation model, particles were backtracked from the Gulf of Mexico spill site to determine the probability of young turtles arriving in this area from major nesting beaches. The...
Article
Full-text available
Many marine species have complex life histories that involve disparate developmental, foraging and reproductive habitats and a holistic assessment of the spatial requirements for different life stages is a challenge that greatly complicates their management. Here, we combined data from oceanographic modeling, nesting surveys, and satellite tracking...
Article
Full-text available
Migration in animals has evolved as an adaptation to environmental variability across space and through time. The availability of reliable sensory cues and guidance mechanisms used in navigating among disparate locations is an essential component of this behavior. An "inherited magnetic map" is navigational solution that has evolved in some marine...
Article
Although oceanic dispersal in larval and juvenile marine animals is widely studied, the relative contributions of swimming behavior and ocean currents to movements and distribution are poorly understood [1-4]. The sea turtle "lost years" [5] (often referred to as the surface-pelagic [6] or oceanic [7] stage) are a classic example. Upon hatching, yo...