David Kroodsma

After the near-complete cessation of commercial whaling, ship collisions have emerged as a primary threat to large whales, but knowledge of collision risk is lacking across most of the world's oceans. We compiled a dataset of 435,000 whale locations to generate global distribution models for four globally ranging species. We then combined >35 billi...

Advancements in space-based ocean observation and computational data processing techniques have demonstrated transformative value for managing living resources, biodiversity, and ecosystems of the ocean. We synthesize advancements in leveraging satellite-derived insights to better understand and manage fishing, an emerging revolution of marine indu...

Accurate assessments of human-wildlife risk associated with industrial fishing are critical for the conservation of marine top predators. Automatic Identification System (AIS) data provide a means of mapping fishing and estimating human-wildlife risk; however, risk can be obscured by gaps in the AIS record due to technical issues and intentional di...

The world’s population increasingly relies on the ocean for food, energy production and global trade1–3, yet human activities at sea are not well quantified4,5. We combine satellite imagery, vessel GPS data and deep-learning models to map industrial vessel activities and offshore energy infrastructure across the world’s coastal waters from 2017 to...

Rapid implementation of human mobility restrictions during the COVID-19 pandemic dramatically reduced maritime activity in early 2020. But where and when activity rebounded, or remained low, during the full extent of 2020 restrictions remains unclear. Using global high-resolution datasets, we reveal a surprising degree of complexity in maritime act...

While most research has focused on the legality of global industrial fishing, unregulated fishing has largely escaped scrutiny. Here, we evaluate the unregulated nature of global squid fisheries using AIS data and nighttime imagery of the globalized fleet of light-luring squid vessels. We find that this fishery is extensive, fishing 149,000 to 251,...

Many fishing vessels use forced labor, but identifying vessels that engage in this practice is challenging because few are regularly inspected. We developed a positive-unlabeled learning algorithm using vessel characteristics and movement patterns to estimate an upper bound of the number of positive cases of forced labor, with the goal of helping m...

Illegal, unreported, and unregulated (IUU) fishing costs billions of dollars per year and is enabled by vessels obfuscating their identity. Here, we combine identities of ~35,000 vessels with a decade of GPS data to provide a global assessment of fishing compliance, reflagging patterns, and fishing by foreign-owned vessels. About 17% of high seas f...

Because many vessels use the Automatic Identification System (AIS) to broadcast GPS positions, recent advances in satellite technology have enabled us to map global fishing activity. Understanding of human activity at sea, however, is limited because an unknown number of vessels do not broadcast AIS. Those vessels can be detected by satellite-based...

Illegal, unreported, and unregulated (IUU) fishing incurs an annual cost of up to US$25 billion in economic losses, results in substantial losses of aquatic life, and has been linked to human rights violations. Vessel tracking data from the automatic identification system (AIS) are powerful tools for combating IUU, yet AIS transponders can be disab...

Unsustainable fishing practices worldwide pose a major threat to marine resources and ecosystems. Identifying vessels that evade monitoring systems -- known as "dark vessels" -- is key to managing and securing the health of marine environments. With the rise of satellite-based synthetic aperture radar (SAR) imaging and modern machine learning (ML),...

Significance Global vessel traffic is increasing alongside world economic growth. The potential for rising lethal ship strikes on endangered species of marine megafauna, such as the plankton-feeding whale shark, remains poorly understood since areas of highest overlap are seldom determined across an entire species range. Here we show how satellite...

Because many vessels use the Automatic Identification System (AIS) to broadcast GPS positions, recent advances in satellite technology have enabled us to map global fishing activity. Understanding of human activity at sea, however, is limited because an unknown number of vessels do not broadcast AIS. Those vessels can be detected by satellite-based...

Marine fisheries in African waters contribute substantially to food security and local economies in African coastal nations. Recently, there are growing concerns about the sustainability of living marine resources in these countries’ exclusive economic zones (EEZs) due to increased risks from climate change, pollution and potential over‐exploitatio...

Understanding encounters between marine predators and fisheries across national borders and outside national jurisdictions offers new perspectives on unwanted interactions to inform ocean management and predator conservation. Although seabird–fisheries overlap has been documented at many scales, remote identification of vessel encounters has lagged...

Significance Forced labor in fisheries is increasingly recognized as a human rights crisis. Until recently, its extent was poorly understood and no tools existed for systematically detecting forced labor risk on individual fishing vessels on a global scale. Here we use satellite data and machine learning to identify these high-risk vessels and find...

Illegal, unreported, and unregulated fishing threatens resource sustainability and equity. A major challenge with such activity is that most fishing vessels do not broadcast their positions and are “dark” in public monitoring systems. Combining four satellite technologies, we identify widespread illegal fishing by dark fleets in the waters between...

The Automatic Identification System (AIS) provides detailed tracks of tens of thousands of industrial fishing vessels, and these detailed tracking data have the potential to provide estimates of fishing activity and effort in near real time. Realizing this potential, though, is not straightforward and depends on the vessel size, gear type, and the...

Small‐scale fisheries contribute substantially to the sustainability of coastal communities by providing livelihood and economic opportunities and ensuring food security. However, their geographic range of operation overlaps with that of industrial fisheries, increasing the resource competition, risk of vessel collision and inter‐sector conflicts,...

European fleets in the northern half of FAO Area 37 have adopted AIS for almost 100 percent of vessels larger than 15 m, whereas African and Middle East countries have extremely low AIS use in southern and eastern areas where AIS reception is also poor. Most vessels broadcasting AIS in the area use high quality Class A AIS devices, and the AIS rece...

The Arctic, due to its extensive ice cover and remoteness, sees comparatively low amounts of industrial fishing. The only areas with many months of ice-free water are off far western Russia and in the waters near the Hudson Bay; partially as a result, all AIS fishing is concentrated in these regions. According to the Global Fisheries Landing Databa...

The United States of America and Canada, which are responsible for most of the fishing activity in the FAO Area 21, have good use of AIS for vessels larger than 24 m. In addition, AIS reception is very good all over the area for larger vessels broadcasting with high-quality Class A AIS devices. However, reception is quite poor for lower quality Cla...

Most vessels over 15 m length in FAO Area 27 broadcast AIS mainly using Class A devices. Class A device reception is good along the coastline where a large network of terrestrial receivers enhances satellite coverage. However, several offshore regions beyond the coverage of terrestrial receivers have poorer reception. These areas are in the North S...

AIS use in this region is dominated by vessels from the United States of America (trawlers in their majority), largely because most other countries in the region have a very low use of AIS. Class A reception is poor in the Gulf of Mexico, missing much of the fishing activity in that zone, but better in the southern and eastern parts of the region....

Most of the fishing activity detected by AIS included fleets from Morocco and distant water fleets from Europe and Asia. In contrast, little activity by west African nations was seen because few vessels in these fleets carry AIS. Trawling, the most important activity identified by AIS in the region, showed clear concentration patterns along the coa...

AIS use is high by Argentina, Uruguay, the Falkland Islands and foreign fleets fishing in the southern half of the area. Farther north, in the Brazilian EEZ, AIS provides a poor assessment of activity due to low use of AIS. The AIS reception for class A is excellent across the area, while it is poor for class B. There is a high number of distant fl...

Based on AIS data, most fishing in the Southern Ocean is conducted by distant water fleets using Class A devices with good reception quality across the region. CCAMLR fishery data reports show that bottom-set longliners and mid-water trawlers are predominant, accounting for 68 percent and 32 percent of fishing days in 2016, respectively. Fishing ac...

Among coastal countries/territories, AIS use is low for Angola and Saint Helena, Ascension and Tristan da Cunha, but significant for South Africa and Namibia. For distant water fleets, with several operating in the region, AIS use is high. AIS Class A and B device reception is good except in northern areas for Class B devices. Trawler intensity and...

In the northern portion of the Western Indian Ocean region, the ability to map fishing activity through AIS data is limited by poor AIS reception and low levels of AIS use in artisanal and semi-industrial fleets from coastal countries. Throughout the region, gillnet is one of the main fishing gears for the artisanal and semi-industrial fleets, but...

Class A AIS device reception is good throughout the area, except in northern areas around the Bay of Bengal. However, Class B AIS device reception is good only in the southern half of the Indian Ocean, and very poor in the northern half including the Bay of Bengal. Fishing activity in the eastern Indian Ocean is poorly represented by AIS data, even...

AIS use in FAO Area 61 is dominated by the Chinese fleet. Because of poor AIS reception in the western part of this region and the difficulties accessing regional fleet registries to verify GFW vessel classification, the usefulness of AIS data to identify the fishing level activity by gear type is very limited in this area. AIS identifies fishing a...

AIS use in the area was relatively low for Mexico and Central America due to the high proportion of domestic near-shore small scale fishing fleets, but high for the United States of America and the distant water fleets. AIS reception was excellent for Class A AIS devices across the entire area. Class B AIS device reception performed poorly in the s...

AIS use is good in the high seas, especially for distant water fleets, but low in the coastal regions. Class A reception is good across the region, while Class B performs well except for vessels operating just outside the South American EEZs. Coastal AIS data, including the highly productive Peruvian fleet fishing anchoveta, is poorly represented i...

Fishing in the Northeast Pacific is dominated by the fleets of the United States of America and Canada, both of which have a high adoption of AIS by larger vessels. AIS Class A reception is excellent, but Class B device reception is medium to poor in most of the area. Trawlers are the most important gear in FAO Area 67, where AIS data highlight wel...

AIS use and reception are extremely poor at the western end of this area, but relatively high and good on the eastern edge. As a result, AIS captures almost none of the important fishing activity in southeast Asia – particularly regarding the domestic fleets. Overall, all gear types are poorly represented except for pelagic longliners and purse sei...

AIS use and reception in this area was relatively high. The exception was reception of Class B devices in the northwestern part of the area. Trawlers and drifting longliners were the most important gears in the area. The trawler industry operating in New Zealand waters appeared well represented in AIS data, but not the demersal activity off Tasmani...

It is well-established that phytoplankton growth can be limited by the vanishingly low concentrations of dissolved iron found in large areas of the open ocean. However, the availability of iron is not typically considered an important factor in the ecology of marine animals, including fish. Here, we compile observations to show that the iron conten...

Human beings are the dominant top predator in the marine ecosystem. Throughout most of the global ocean this predation is carried out by industrial fishing vessels, that can now be observed in unprecedented detail via satellite monitoring of Automatic Identification System (AIS) messages. The spatial and temporal distribution of this fishing effort...

A methodology had been proposed for cross-matching visible infrared imaging radiometer suite (VIIRS) boat detections (VBD) with vessel monitoring system (VMS) tracks. The process involves predicting the probable location of VMS vessels at the time of each VIIRS data collection with an orbital model. Thirty-two months of Indonesian VMS data was segm...

Many species of sharks and some tunas are threatened by overexploitation, yet the degree of overlap between industrial fisheries and pelagic fishes remains poorly understood. Using satellite tracks from 933 industrial fishing vessels and predictive habitat models from 876 electronic tags deployed on seven shark and tuna species, we developed fishin...

Amoroso et al. demonstrate the power of our data by estimating the high-resolution trawling footprint on seafloor habitat. Yet we argue that a coarser grid is required to understand full ecosystem impacts. Vessel tracking data allow us to estimate the footprint of human activities across a variety of scales, and the proper scale depends on the spec...

Automatic Identification Systems (AIS) are a standard feature of ocean-going vessels, designed to allow vessels to notify each other of their position and route, to reduce collisions. Increasingly, the system is being used to monitor vessels remotely, particularly with the advent of satellite receivers. One fundamental problem with AIS transmission...

The patterns by which different nations share global fisheries influence outcomes for food security, trajectories of economic development, and competition between industrial and small-scale fishing. We report patterns of industrial fishing effort for vessels flagged to higher- and lower-income nations, in marine areas within and beyond national jur...

Surface mining for coal has taken place in the Central Appalachian region of the United States for well over a century, with a notable increase since the 1970s. Researchers have quantified the ecosystem and health impacts stemming from mining, relying in part on a geospatial dataset defining surface mining’s extent at a decadal interval. This datas...

Transshipment at sea, the offloading of catch from a fishing vessel to a refrigerated vessel far from port, can obscure the actual source of the catch, complicating sustainable fisheries management, and may allow illegally caught fish to enter the legitimate seafood market. Transshipment activities often occur in regions of unclear jurisdiction whe...

While the ecological impacts of fishing the waters beyond national jurisdiction (the “high seas”) have been widely studied, the economic rationale is more difficult to ascertain because of scarce data on the costs and revenues of the fleets that fish there. Newly compiled satellite data and machine learning now allow us to track individual fishing...

Between 1950 and 1989, marine fisheries catch in the open-ocean and deep-sea beyond 200 nautical miles from shore increased by a factor of more than 10. While high seas catches have since plateaued, fishing effort continues to increase linearly. The combination of increasing effort and illegal, unreported and unregulated (IUU) fishing has led to ov...

More than half the fish in the sea As the human population has grown in recent decades, our dependence on ocean-supplied protein has rapidly increased. Kroodsma et al. took advantage of the automatic identification system installed on all industrial fishing vessels to map and quantify fishing efforts across the world (see the Perspective by Polocza...

Recently, Popular Science disabled its online comments. In explaining this decision, the magazine cited research that showed that online comments, especially uncivil ones, strongly influence readers, often leading to misleading or incorrect interpretations of the articles. Popular Science wrote, “If you carry out those results to their logical end…...

To better understand agricultural carbon fluxes in California, USA, we estimated changes in soil carbon and woody material between 1980 and 2000 on 3.6 x 10(6) ha of farmland in California. Combining the CASA (Carnegie-Ames-Stanford Approach) model with data on harvest indices and yields, we calculated net primary production, woody production in or...