Using GIS to Manage Cetacean Strandings
INTRODUCTION
Even though cetaceans are known by men since early history, with records of interactions between humans and dolphins in the writings of Pliny the old, in 23 b.C. ( and 1999), the knowledge regarding these animals still lags behind land mammals. This is mostly because the fact that they spend only a small amount of time on the surface, being difficult to observe them. Allied to this, the sea does not record any tangible signs of their passage or use of the area, such as footprints, scats or dens, which are commonly used by researchers to investigate the habits of terrestrial mammals. A method that cetologists have used to gather information about the ecology and social lives of these animals is by investigating single or mass strandings.
Most of the time, they are already dead when stranding, which restricts the data that can be obtained from such events.
On the other hand, some kinds of data can only be obtained from dead animals, such as stomach contents. Therefore stranded, or bycaught, animals were the base for a large number of scientific works dealing with the trophic aspects of cetaceans (
, 1980; and , 2001). In other
cases dead animals from strandings helped to understand the impact of fisheries on cetaceans ( , 1975; and , 1999) or to unravel the intricacies of their social
lives ( , 1993; ., 2000). Even the
distribution of many species are known only from the location
where animals have stranded ( ;
, 2002), which is far from adequate considering that many specimens may strand after being dead for a considerable amount of time and thus were under the action of currents. Thus, determining the distribution of a cetacean species by strandings should be taken with care.
The inherent characteristics of a stranding (unique, isolated, non-reproductible) make the publication of works dealing with them very difficult. As a result, except for rare species, most strandings are made available for the scientific community only as conference abstracts, if ever. Also, along the Brazilian coast systematic efforts for recording strandings are scarce (
and , 1999; , 1999), and stranding networks have only recently started to be structured (IBAMA, 2000) with stranding records being in most part oportunistic.
On the other hand, if the details of most strandings could be integrated into a single database, this would be extremely
valuable for coastal management. Such a database would allow identifying critical areas for marine mammals and find out areas with more or less records of each species. Thus, this work presents the characteristics of a developed specifically for the analysis of cetacean strandings on the Brazilian coast.
Strandings are, by its onw nature, strewn over wide areas and so are collected by many individuals. Considering the extent of the Brazilian coast, collaboration and sharing of data usually occurs among neighbouring research groups. On a larger scale, this exchange of information requires that the groups know each other, and thus data from emerging research groups are usually overlooked. At the moment, the most expedite way to share, and search for, information is the internet. Therefore a web-based system is the option of choice.
The system was based on RASTRO, a successful webGIS application developed by the Applied Computing Laboratory of CTTMar, UNIVALI. The technologies used in the system were selected using two major criteria: web born capabilities and open source nature. Exceptionally, the database management system (DBMS) adopted was Oracle, with the Spatial Database Objects expansion cartridge (SDO). Underlying the DBMS is the Red Hat Linux operating system, integrated with the Apache web server, the PHP script-processing module and the MapServer technology sponsored by University of Minnesota and the TerraSIP project. Combined, this is the platform that sustains the RASTRO system (Figure 1), which uses PHP scripts for web user interfaces; and Linux shell scripts for automation ( , 2003).
The inclusion of new users for the system can be done only by the system administrator. Users will only be given access to REYNOLDS
ROMMEL,
CLARKE SANTOS HAIMOVICI
BROWN PINEDO
POLACHEK
AMOS FULLARD
REEVES
PINEDO POLACHECK SANTOS
CABRAL
e.g.
et al.
et al. et al
e.g. Indopacetus pacificus et al.
e. g.
webGIS
et al.
SYSTEM STRUCTURE
Access to the system is divided in two levels: public and restricted. Public areas are limited to a general map of stranding locations, with species and the person responsible for this information, but no information on the number of animals or the date of the stranding event. The restricted area is accessed by a login/password pair, and allows the inclusion and editing of data. It must be stressed out that each user only has access to data entered by himself. This, and the relative small amout of data available to public users, is to guarantee that use of data (scientific or otherwise) can only be done with consent of the person responsible for inputting it on the database.
Journal of Coastal Research SI 39 1643 - 1645 ICS 2004 (Proceedings) Brazil ISSN 0749-0208
A. S. Barreto*†; C. G. Moraes*§; R. M. Sperb*‡ and C.H. Bughi * ‡ ‡
* Universidade do Vale do Itajaí - UNIVALI Centro de Ciências Tecnológicas da Terra e do Mar - CTTMar,
Itajaí SC, 88302-202, Brazil
BARRETO, A. S.; MORAES, C. G.; SPERB, R. M. and BUGHI C.H., 2006.Using GIS To Manage Cetacean Strandings. Journal of Coastal Research, SI 39 (Proccendigs of the 8th International Coastal Symposium), 1643 - 1645. Itajaí, SC, Brazil, ISSN 0749-0208.
Much of what is known of cetacean distribution was discovered through stranded animals. Information obtained from stranded animals were the base for a large number of scientific works, including the distribution of many species. The inherent characteristics of a stranding (unique, isolated, non-reproductible) make the publication of works dealing with them very difficult. On the other hand, the information that could be obtained if the details of most strandings could be integrated into a single database, would be very valuable for coastal management since it could point out areas with more or less risk for marine mammals. In order to integrate such data, a webGIS application was developed, to establish a georeferenced framework to generate dinamic maps, with data entry using a web environment. The system is being tested with data available on the literature, and could be used as a tool to monitor the mortality of cetaceans on the Brazilian coast.
ADDITIONAL INDEX WORDS:Sighting, network, Brazil.
ABSTRACT
† Lab. Oceanografia Biológica - abarreto@univali.br
§ Lab. Oceanografia Biológica - cristianeg_moraes@hotmail.br
‡ Lab. Computação Aplicada - rsperb@univali.br Lab. Computação Aplicada - bughi@univali.br
Journal of Coastal Research Special Issue 39, 2006,
the system after signing a ter
won't use data contained in SIMMAM in any publication or commercial application without prior written consent of the original data provider and to cite both SIMMAM and the data provider in any publication that arises from the data. The same term os use will have to be accepted on-line by anonymous users
any kind of query to the database.
Given that data would come from different research groups, originally it wouldn't be in a standard format, and indeed there could be significant differences in the nature of the data collected. So, the choice of variables to be included in the database was made considering the minimum amount of data needed to uniquely identify the stranding:
At the moment of this writing, this project is a work in progress (Figures 2 and 3). The database is being initially fed with data obtained from the literature, since this information is now in the public domain. Instead of relating the data points from the literature to a specific database user, the source will be a bibliographic reference.
One of the main venues of scientific exchange for marine mammalogists in South America are the “Meetings of South American Specialists in Aquatic Mammals” (
) which have been happening every even year since 1984. Abstracts of works presented at these meetings have many stranding reports, many of which weren't used in scientific papers. Thus, their inclusion will be the starting point from which the Brazilian scientific community will be able to consider the usefulness of a central database of stranding records.
In order to decrease operational costs, the system is being prepared to migrate from Oracle to Postgre/PostGIS, since it is the philosophy of the Applied Computing Laboratory to use open-source software. PostGIS is an extension to the PostgreSQL object-relational database system which allows GIS objects to be stored in the database ( , 2003).
To help understanding biogeographic patterns and mortality events, it's planned to include layers in the webgis for surface temperature and productivity (chlorophyll). Including this information will enable system users to analyse their data relative to environmental variables and correlate species occurrence with oceanographic patterns.
when performing
Date;
Position (latitude, longitude);
Species;
Number of animals; and
Specimens collected (collection numbers);
Since all data inclusion or editing is connected to a login, the accuracy of the information is the responsibility of each researcher.
Considering that the main objective was to manage strandings, there was little use for ancillary data such as environmental parameters at the moment the animal was found.
The majority of records of strandings in the Brazilian coast are of dead animals and thus data on environmental factorsd at the moment the animal was found wouldn't probably be correlated with the cause of death or distribution of the animal.
However, it was decided to include such data in the database after taking into account that the same framework could be used for managing cetacean sightings. As discussed above, the location of a stranding can't be reliably used for estimating the distribution of a species. However, inclusion of data from surveys in adjacent waters might also be helpful in understanding patterns of cetacean distribution. For this second class of data, environmental parameters are crucial and should be stored associated with sighting data.
At-sea sightings can also be used to gather information about distribution, but more importantly they allow estimating cetacean densities. Data used to understand distribution are identical to data from strangings, with the exception that only rarely specimens will be collected ( DNA samples). On the other hand, data for estimating densities have very different characteristics. Firstly, environmental information (weather, sea state, wind speed and direction) is essential since they modify the probability of sighting an animal. And secondly, data on sighting effort (duration, track length and location) and the sighting itself (sighting cue, group size, distance from trackline) are fundamental for estimation models (
, 1993).
We believe that when the system is fully operational and in use by different researchers along the Brazilian coast, it will
e.g.
et al.
BUCKLAND
RESULTS
Reunión de Trabajo de Especialistas en Mamíferos Acuáticos de América del Sur
RAMSEY
m of use which states that they
Barretoet al.
Figure 1. System architecture. Source:CABRALet al., 2003.
Figure 3. System's webgis interface.
Figure 2. System's web interface (www.univali.brg10).
Journal of Coastal Research Special Issue 39, 2006, 1644
allow a new level of collaboration between research goups and individuals. Every researcher will be able to know where there were strandings of every species in which they are interested and find the contact information for the persons who were responsible for collecting data of its strandings. Instead of relying only on networks of acquaintances to know who is working where along the coast, it will be possible to find where each researcher has collected data in a given period of time.
Finally, what was up to now done painstakingly reviewing scientific meeting abstracts and papers, will be done from a single website.
W.; C. and D., 1993. Social
structure of Pilot Whales revealed by analytical DNA profiling. , 260, 670-672.
S.G., 1975. Relation between stranding mortality and population abundance of smaller cetacea in the northeast atlantic ocean.
, 32, 1095-1099.
and
LITERATURE CITED
AMOS, SCHLOTTERER, TAUTZ,
BROWN,
Science
Journal of the Fisheries Research Board of Canada
BUCKLAND, S. T.; ANDERSON, D. R.; BURNHAM
LAAKE,
CABRAL, R. B.; SPERB, R. M.; TRIPODI, R. Z.; WAHRLICH, R.;
SOUZA, J
CLARKE, MACLEOD, CASTELLO, PINEDO,
FULLARD, K. J.; EARLY, G.; HEIDE-J RGENSEN, M. P.; BLOCH, D.; ROSING-ASVID, AMOS,
PINEDO, POLACHECK,
RAMSEY,
REEVES, STEWART, CLAPHAM, POWELL,
REYNOLDS, ROMMEL,
SANTOS, DE
SANTOS, HAIMOVICI, , K. P. and
J. L., 1993. Distance Sampling Estimating Abundance of Biological Populations. London: Chapman
Hall, 446 p.
., 2003. RASTRO: Internet Based Tracking System for Fisheries Control. Fifth International Symposium on GIS and Computer Cartography for Coastal Zone Management. Available on-line at h t t p : / / w w w . g i s i g . i t / c o a s t g i s / p r o g r a m m a / abstract/becke_cabral.htm. Accessed in 20-nov-2003.
M.R.; N.; H.P. and
M.C., 1980. Cephalopod Remains from the Stomach of a
Sperm Whale Stranded at Rio Grande do Sul in Brazil.
, 59, 235-239.
A. and W., 2000. Population structure of long-finned pilot whales in the North Atlantic: a correlation with sea surface temperature?
9, 949-958
IBAMA, 2000. Brasilian Institute for the Environment and Renewable Natural Resources, Regulation 039, 28-VI- 2000, 3p.
M.C. and T., 1999. Trends in franciscana
( ) stranding rates in Rio Grande do
Sul, Southern Brazil (1979-1998).
, 1, 179-189.
P., 2003. . Available on-line at http://postgis.refractions.net/docs/. Accessed in 20-nov- 2003.
R.R.; B.S.; P.J. and
J.A., 2002. .
National Audubon Society. Chanticleer Press edition, New York, 527 pp.
J.E. and S.A. 1999.
. Smithsonian Institution Press, Washington, 578 p.
M.C. O., 1999. Novas informações sobre cetáceos no litoral sul de São Paulo e norte do Paraná com base em estudos sobre encalhes e na aplicação da técnica de foto- identificação individual de (Cetacea, Delphinidae). Master's thesis. USP, São Paulo. 144p.
R.A. and M., 2001. Cephalopods in the diet of marine mammals stranded or incidentally caught along the southeastern and southern Brazil (21 - 34 S).
, 52, 99-112.
Marine Biology
Molecular Ecology
Pontoporia blainvillei
Journal of Cetacean Research and Management
PostGIS Manual
Guilde to Marine Mammals of the World
Biology of Marine Mammals
Sotalia fluviatillis
Fisheries
Ø
o
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