Annotated Bibliography Use of Global Information Systems in Fish Tagging

Transcription

1 Lena Weiss Applications of GIS and Remote Sensing in Fish Tagging Studies The utilization of fish tagging has proved to be an extremely useful tool for determining many different characteristics of fishery population dynamics, including movement, growth, and habitat utilization patterns. Over the years, there has been an increase in the technological capabilities of fish tags, which extend far beyond traditional mark and recapture techniques. Acoustic tags, which emit constant audio signals that can be tracked actively by boat or passively via listening stations; and satellite tags, which are designed to continuously collect and store both movement and environmental data over a fixed period of time, are capable of providing a much more robust and accurate picture of fish movements. In order to properly interpret the high resolution data that these tags collect, visualization and analytical techniques utilizing GIS and remote sensing technology have become increasingly popular in this field of research. Since GIS and remote sensing are extremely flexible research tools, studies integrating this type of technology are extremely wide-ranging in both scope and design. Overall, many studies in this area have focused on providing movement and habitat use patterns over both the short-and long-term. Such studies have been conducted in both marine and freshwater environments, in both deep and shallow water, and on species of fish ranging from the very small (young-of-theyear Atlantic salmon) to the very large (whale sharks). These wide ranges of uses demonstrates the wide applicability of these techniques in the realm of fisheries population dynamics. Besides providing valuable basic biological information on specific fish populations, fish tagging studies utilizing GIS/RS have also aimed to assist with conservation efforts of these populations. For example, a study conducted in the Mississippi River aimed to determine the levels of connectivity between small sub-populations of paddlefish, a threatened species, and if this connectivity was affected by the current placement of dams on the river (Zigler et al., 2003). Another study, conducted in inshore reef areas in the Azores, attempted to determine if the present design of a marine protected area accurately reflected the habitat use patterns of the white trevally (Afonso et al, 2009). The findings of such studies have direct implications in the realm of fisheries management. Furthermore, since the utilization of fish tags with enhanced data collection capabilities is a fairly new field, some studies have chosen to test new methods of data acquisition and analysis while simultaneously collecting simple fish movement information. This is especially true in the case of satellite tags, which are an emerging technology. For example, one researcher noticed that satellite tags had difficulty estimating latitude, since the sensors in PSAT tags are lightbased, and thus are more susceptible to errors near equinoxes and at low latitudes. As a result, he developed and tested an automated algorithm that uses remotely-sensed sea-surface temperature data to estimate latitude (Domeier et al, 2005). Another researcher wished to test the applicability of satellite tags that had been designed for use on Bluefin tuna on swordfish, a much deeper-

2 swimming fish (Sedberry &Loefer, 2001). Exploratory studies such as these help to contribute to the wide diversity of uses we see in current fish tagging research. The data used to supplement the basic GPS position data collected in fish tagging studies is just as diverse. Studies conducted using satellite tags have supplemented position data with sea surface temperature information, collected from sources including: Advanced High Resolution Radiometry satellites (ACHEE), Advanced Very High Resolution Radiometry (AVHRR), Moderate Resolution Spectroradiometer (MODIS), and the Multi-channel Sea Surface Temperature Algorithm (MSCSST) (Domeier et al, 2005, Sedberry & Loefer). This information serves as checks to the information collected by the satellite tags. Other studies have collected bio-geophysical information in situ, since active tracking of acoustic tags requires the researchers to re-find the fish by boat (Parsons et al, 2003; Steingrimsson & Grant, 2003; Zigler et al, 2003). Finally, projects taking into account habitat considerations, such as bottom topography, bathymetry, and current velocity have turned to government databases, such as the NOAA National Geophysical Data Center and the USGS Long Term Resource Monitoring Program, and have incorporated this information as bottom layers in their GIS maps (Sedberry & Loefer, 2001; Zigler et al, 2003). Using bio-geophysical data such as sea surface temperature, bottom topography, and bathymetry allow researchers to take into account external variables that may account for observed movement patterns. Once movement information and environmental variables have been collected, data is then modeled and analyzed using GIS software. Most fish tagging studies that use GIS/RS use it as a supplement to more traditional statistical analysis. Thus, it is helpful to think of GIS in this field as more of a data visualization tool, rather than an analytical one. The simplest way to display fish movement patterns is as straight lines between transmitted points. This method, known as tracks, is created through Animal Movement Extension Software, an application of ArcGIS (Zamora & Moreno-Amich, 2002). However, it does not seem to be a very popular method, since it assumes straight-line movement, which may not be the most accurate for all species. A much more popular method is to display movement as use contours. Use contouring uses time spent in an area as the unit of analysis, and delineates between areas in which individuals spend more time versus areas in which individuals spend less time (darker pixels represent more time spent in that area). This gives a more intuitive picture of core versus peripheral habitat for the tagged species (Parsons et al, 2003). Many studies focused on determining the home range of a population of fish, and utilized kernel utilization distribution (KUD) alongside minimum convex polygon areas (MCP). Both of these analyses also utilize Animal Movement Extension Software. KUD is a probabilistic method that calculates the area of probability of finding a fish using position data, and helps to determine core and total activity area, while MCP is a display mechanism in which the relative size of the polygon indicates the average daily presence of a fish within a given tagging group (Domeier et al, 2004; Afonso et al, 2009).

3 Finally, several studies focused on determining habitat preference and suitability by overlaying fish movement on top of bio-geophysical data. For example, Sedberry& Loefer (2001), overlaid swordfish movements on top of bottom topography and sea surface temperature, using Image Analyst Extension for ArcView. They determined that swordfish appeared to be attracted to complex high-relief bottom structures and complex thermal structures, such as those found in the Charlestown Bump off the coast of the Carolinas. Additionally, Zigler et al (2003) used a Spatial Analyst Model, along with position information and a habitat suitability index, to create a comprehensive cartographic model showing the seasonal use of aquatic area types of paddlefish. This study was able to show strong differences in the use and selection of aquatic area types, with current velocity and water depth as strong determinants of paddlefish habitat. Habitat analyses such as these help to provide explanations of movement patterns and potential habitat preferences, useful information for conservation and management efforts. Overall, the application of GIS and remote sensing into fish tagging studies is a helpful visualization tool for determining and analyzing fish movement patterns. It appears to be especially good for sensors that provide frequent data, such as acoustic and satellite tags. Taken as a whole, this type of analysis appears to be especially helpful for fisheries conservation and management, for example, determining where a marine protected area would be most helpful for a given fish population. Furthermore, studies integrating fish movement with bio-geophysical data appear to provide a more robust picture of the underlying causes of observed movement patterns. However, there are several drawbacks to this type of research that will hopefully be addressed in the future. First, acoustic and satellite tags are expensive to purchase and use; therefore, most of the studies found had relatively small sample sizes (n<30). Additionally, over the course of the studies, it was typical for the researchers to lose one or two tags due to malfunction or external human factors (i.e. the fish was caught). These two factors limit the statistical power of any analyses conducted, and thus their wider applicability. Hopefully, as our technological capabilities increase, tags such as the PSAT satellite tag will become cheaper and easier to use, allowing scientists to increase their sample size, addressing this problem. Finally, no study that I found integrated human use patterns, such as fishing effort, into their analyses. While this type of position information is relatively scare, it does exists in some areas, and is being collected increasingly frequently. Hopefully, in the future, some tagging studies will focus on coupled human-ecological systems to provide a better understanding to how fisheries respond to differing levels of fishing pressure.

4 Work Cited Afonso, P., Fontes, J., Holland, K. N., & Santos, R. S. (2009). Multi-scale patterns of habitat use in a highly mobile reef fish, the white trevally Pseudocaranx dentex, and their implications for marine reserve design. Marine Ecology Progress Series, 381, doi: /meps07946 Domeier, M. L., Kiefer, D., Nasby-Lucas, N., Wagschal, A., & O Brien, F. (2005). Tracking Pacific Bluefin tuna (Thunnus thynnus orientalis) in the northeastern Pacific with an automated algorithm that estimates latitude by matching sea-surface-temperature data from satellites with temperature data from tags on fish. Fishery Bulletin, 103(2), Parsons, D., Babcock, R., Hankin, R., Willis, T., Aitken, J., O'Dor, R., & Jackson, G. (2003). Snapper Pagrus auratus (Sparidae) home range dynamics: acoustic tagging studies in a marine reserve. Marine Ecology Progress Series, 262, Sedberry, G., & Loefer, J. (2001). Satellite telemetry tracking of swordfish, Xiphias gladius, off the eastern United States. Marine Biology, 139(2), Steingrímsson, S. Ó., & Grant, J. W. A. (2003). Patterns and correlates of movement and site fidelity in individually tagged young-of-the-year Atlantic salmon (Salmo salar). Canadian Journal of Fisheries and Aquatic Sciences, 60(2), doi: /f Zamora, L., & Moreno-Amich, R. (2002). Quantifying the activity and movement of perch in a temperate lake by integrating acoustic telemetry and a geographic information system. Hydrobiologia, 483(1-3), Zigler, S. J., Dewey, M. R., Knights, B. C., Runstrom, A. L., & Steingraeber, M. T. (2003). Movement and Habitat Use by Radio-Tagged Paddlefish in the Upper Mississippi River and Tributaries. North American Journal of Fisheries Management, 23(1), doi: / (2003)023<0189:mahubr>2.0.co;2

5 Annotated Bibliography Use of Global Information Systems in Fish Tagging Afonso, P., Fontes, J., Holland, K. N., & Santos, R. S. (2009). Multi-scale patterns of habitat use in a highly mobile reef fish, the white trevally Pseudocaranx dentex, and their implications for marine reserve design. Marine Ecology Progress Series, 381, doi: /meps07946 This study attempted to determine the movement and habitat use patterns of the white trevally (a commercially important shallow reef fish) in inshore and offshore reefs in the Azores. The purpose of this study was to assist in the design of marine protected areas that would be appropriate for managing the fish species. The researchers used both traditional and acoustic tags, and utilized a combination of active and passive (via listening stations) tracking for varying periods of time to monitor fish behavior. They then calculated daily activity area size using kernel utilization distribution (KUD) and minimum convex polygon areas (MCP) through animal movement software in ArcView GIS. The researchers found that offshore fish never left the reef, whereas coastal fish moved extensively along the coastline, and that home ranges also varied depending on the time of year. This study stressed the challenges and limitations of using marine reserves as a spatial refuge tool for highly mobile fishes, when a more effective measure may be seasonal closures of the area from fishing. Although this study provided new and important information regarding the movement patterns of the white trevally, a major limitation of the study was the fact that only seven fish were monitored actively, and only 32 fish were monitored passively using acoustic telemetry (probably due to the expense). The small sample size precludes the researches from making any substantial generalizations about the movement patterns of an entire fish population. Domeier, M. L., Kiefer, D., Nasby-Lucas, N., Wagschal, A., & O Brien, F. (2005). Tracking Pacific Bluefin tuna (Thunnus thynnus orientalis) in the northeastern Pacific with an automated algorithm that estimates latitude by matching sea-surface-temperature data from satellites with temperature data from tags on fish. Fishery Bulletin, 103(2), The purpose of this study was to test the use of electronic tags and a newly developed sea surface temperature based geolocation algorithm to further the understanding of Bluefin tuna movements in the eastern Pacific. This algorithm was designed to operate in a GIS environment, allowing for rapid analysis and display of archival and PSAT tag data. Estimating latitude is a problem for researchers because the sensors on PSAT tags are light-based, meaning that errors are more likely to occur near equinoxes and when the tag is at low latitudes. Using sea surface temperature (accessed from remotely sensed AVHRR, MODIS, and MCSST data) can possibly provide a better estimate for latitude in these situations. Despite the very small sample size (14 fish), the researchers found that tuna follow a general summer-fall movement northward

6 followed by a winter migration southward and a winter-spring holding pattern around Baja, California (using the new algorithm, fixed kernel home range analysis, and contours of seasonal spatial use and movement). The researchers felt as though the new PSAT tracker algorithm provided quick and automated geolocation estimates, however, they did not want to draw strong conclusions because of the small sample size of their study. The researchers also felt as though a major limitation of their algorithm is that it cannot be used in areas that lack a strong north-south temperature gradient. I liked the fact that the researchers thought of changes in sea surface temperature as a good proxy for latitude, however, as they pointed out, a lot rides on the accuracy of the satellite based SST data. If there is a glitch in the system, or if reporting breaks down, these kinds of studies can be put at risk, especially if the data collection is only for the short-term. Heyman, W. D., Graham, R. T., Kjerfve, B., & Johannes, R. E. (2001). Whale sharks Rhincodon typus aggregate to feed on fish spawn in Belize. Marine Ecology Progress Series, 215, This paper was the first to document that whale sharks target the freshly released spawn of large reef fishes, alongside krill, copepods, crab larvae, small fishes, and squid. The study also attempted to confirm reports of a whale shark aggregation at Gladden Spit (Belize) in April and May each year, which may coincide with snapper spawning aggregations. Observations of whale sharks were made in person using SCUBA. To analyze site fidelity, 14 sharks were tagged, and the geographic location of the tagging point was recorded with a GPS. The locations were then plotted along with the location of the reef and the spawning aggregation using Arc-Info and Arc View GIS. The study was able to confirm a seasonal aggregation of whale sharks at Gladden Spit, coincident with snapper spawning aggregations (based on visual observation). This new biological linkage suggests that the fish spawning aggregations should be protected, since they are highly vulnerable from extirpation from fishing and also provide an important food source for the whale sharks. While this study lacked a large amount of mathematical rigor (statistical analysis), I thought it was a really nice example of scientists helping to substantiate local knowledge (fisher reports of whale shark aggregations). Despite the study's simplicity, it shed light onto an important ecological linkage between species that would have gone unnoticed otherwise. Parsons, D., Babcock, R., Hankin, R., Willis, T., Aitken, J., O'Dor, R., & Jackson, G. (2003). Snapper Pagrus auratus (Sparidae) home range dynamics: acoustic tagging studies in a marine reserve. Marine Ecology Progress Series, 262, This study aimed to describe the movements of resident snapper within the CROP Marine Reserve in New Zealand using a radio-acoustic positioning and telemetry (RAPT) system to track individuals over period of a few months. The study also presents a new method of estimating home ranges where time is used as the contouring variable. The RAPT system allowed accurate positioning (1-2m) of individual fish with a temporal resolution of minutes. The tracking area was divided into 20x20m bins, and the amount of time individual fish were detected in each of the bins was calculated. The bin times were contoured in ArcView, with each contour representing the percentage of time that an individual fish resided within that area.

7 Within each home range, core areas were defined as areas of >50% usage greater than 40m in diameter. The tagged fish had more than one core area in at least one of the monitoring periods, and usage patterns were not uniform over time. This suggests that the carrying capacity of as reserve cannot be calculated by dividing area by the average size of a snapper home range and that movements between different areas are not restricted by the possibility of entering another snapper s home range. I felt as though this study challenged a lot of traditional management assumptions namely that fish movements are regular and predictable over time. However, once again, I felt as though small sample size is a major limitation in making generalizable assumptions with this study only five fish were tagged and monitored. Sedberry, G., & Loefer, J. (2001). Satellite telemetry tracking of swordfish, Xiphias gladius, off the eastern United States. Marine Biology, 139(2), Traditional tagging of highly migratory species such as swordfish has given some information regarding the movement and growth of such species, but this method is not useful for determining residence times and short-term movements. Satellite pop-off tags are a relatively new technology designed to provide a fishery-independent measure of distance traveled from tagging point to release point without the need to recapture the fish. The purpose of this study was to evaluate the use of satellite pop-off tags for tracking deep-swimming fishes and to track the movements of swordfish captured near the Charleston Bump, which has been suspected to be a resident feeding ground for small swordfish. The tagging locations and pop-off locations of 29 swordfish were plotted on bottom topography and sea surface temperature (SST) images, with positions geo-referenced using the Image Analyst Extension for ArcView. Of the 29 tags, 23 released successfully and made contact with the Argos system. The data suggested a large amount of vertical movement undertaken during daily migrations of the swordfish. The data also suggested that swordfish appeared to be attracted to complex high-relief bottom structure and complex thermal structures, such as the Charlestown Bump. Overall, the study suggests that the tags developed for Bluefin tuna may also work on swordfish, but that the swordfish may occasionally dive deeper than the tags are designed to withstand. Satellite tags appear to be a good way to track the short-term movements of large fish, however, it seems to be a much more labor- and data-intensive process than traditional mark-recapture studies. Steingrímsson, S. Ó., & Grant, J. W. A. (2003). Patterns and correlates of movement and site fidelity in individually tagged young-of-the-year Atlantic salmon (Salmo salar). Canadian Journal of Fisheries and Aquatic Sciences, 60(2), doi: /f This study describes the patterns of movement and site fidelity in individually tagged young-of-the-year (YOY) Atlantic salmon. Unlike other studies, this one attempted to use noninvasive techniques for the capture and release of fish. For each of the 291 tagged fish, the local population density was estimated by viewing the distribution of individuals in ArcView and was calculated as the number of YOY salmon within a 2-m radius from the fish divided by the circle area within the stream boundaries. In this study, most re-sighted YOY salmon moved extremely short distances over their first summer of feeding. Fish found in slow water moved farther than fish in fast water, and fish found in high population densities were less likely to be found in the same area. This study supports the idea that fish moving longer distances are not necessarily of

8 lower fitness, and that movement of stream fish can be advantageous, as mobile fish in the study tended to be larger than sedentary fish. The study concluded that there is a need for more rigorous quantitative modeling of movement curves, along with an understanding of the social and environmental conditions that shape these curves in natural habitats. I found it ironic that of all the studies so far, this one had the largest sample size, but refrained from making any strong conclusions about the data gathered. A possible drawback of this research was the use of traditional, rather than acoustic tags, which meant that data was stronger for fish that were more sedentary, since they were more likely to be recaptured. Zamora, L., & Moreno-Amich, R. (2002). Quantifying the activity and movement of perch in a temperate lake by integrating acoustic telemetry and a geographic information system. Hydrobiologia, 483(1-3), This study attempted to analyze the success of the perch invasion of Lake Banyoles, in northeastern Spain, by describing the swimming activity of the perch in the lake and by analyzing daily activity and distribution patterns. Seven perch were tagged using small ultrasonic tags, and were tracked using a radio-linked acoustic positioning array. The data collected were brought into ArcView and were analyzed using Animal Movement Extension software, which sets movement paths. During the study, the transmitter of one perch failed, and four perch moved outside of the array and needed to be tracked manually. The researchers found that perch were most active at dawn and at dusk, possibly related to light-driven feeding patterns. They also found that the fish showed strong site fidelity to the littoral zone. What I liked most about this study was its clear description of both the advantages and disadvantages of acoustic telemetry, as well as a description of how the data from the tags was brought into GIS and manipulated, an element I found lacking in the other papers. Zigler, S. J., Dewey, M. R., Knights, B. C., Runstrom, A. L., & Steingraeber, M. T. (2003). Movement and Habitat Use by Radio-Tagged Paddlefish in the Upper Mississippi River and Tributaries. North American Journal of Fisheries Management, 23(1), doi: / (2003)023<0189:mahubr>2.0.co;2 The restoration of paddlefish populations is a goal of many state and federal agencies. However, the lack of information on paddlefish movements and distribution, as well as the effects of habitat alterations on life history and habitat needs, represent obstacles to paddlefish conservation and restoration. This study aimed to evaluate the long-term movement patterns of paddlefish that may link populations in different tributaries and reaches of the upper Mississippi River and to identify the key aquatic area types and habitat features selected by paddlefish in the upper Mississippi throughout the entire year. The researchers attached radio transmitters to 71 paddlefish, and tracked them manually using GPS. Coordinates were uploaded to ArcView, and the seasonal use of aquatic area types by individual paddlefish was estimated. In one stretch of river with rich GIS data, paddlefish habitat was analyzed in detail, using a Spatial Analyst Module. The researchers found that there was some overlap in the range of the paddlefish, indicating that the population is somewhat connected, and not fully isolated by dams or fish behavior. The researchers also found strong differences in use and selection of aquatic area types, with current velocity and depth serving as important determinants of paddlefish habitat.

9 The researchers conclude that the ability of paddlefish to move through channel corridors that have been extensively modified by dams in both the main river and tributaries is crucial for the recovery of paddlefish in the upper Mississippi. I thought that this paper presented the best use and integration of GIS software into the analysis, with clearly beneficial results.