Sampling Sites

Field Study Sites

In a normal year the Biomonitoring Program will undertake full-scale of monitoring of approximately 430 sites, spanning a range of conditions from large rivers to tiny brooks, pristine wilderness sites to heavily impacted streams, sea level to 200 m. altitude with site selection based on the following criteria:

Reference Sites: These comprise an assortment of sites representing the “best” (least altered by human activity) sites in a variety of stream categories.  Data from these sites is used to establish standards applied in monitoring and interpreting results from other sites.

Fixed Stations : We have now accumulated enough information to be able (in Costa Rica) to designate several fixed stations, to be monitored annually as a barometer of general conditions in Talamanca.

Local requests : Local interest is always a priority for us in selecting monitoring sites.  To the greatest degree possible we try to honor requests for monitoring services from local individuals, communities or conservation groups.

Educational sites : A few individual sites have been and will continue to be monitored in conjunction with specific schools; others simply correspond well to pedagogical needs.

Perceived changes or threats : Some sites will be selected because of perceived changes (for better or worse) or threats.  Factors under this category range from restoration projects to fish kills.

Relation to protected areas : Our work area includes several Protected Areas such as the Hitoy/Cerere Biological Reserve and Gandoca/Manzanillo Wildlife Refuge in Costa Rica and the Palo Seco Forest Reserve and San San/Pondsak Wetland of International Importance in Panama, but of particular significance is the huge La Amistad International Peace Park, a World Heritage Site which constitutes a major biodiversity “Hot Spot”.  One of the most important developments during the life of the ANAI Stream Biomonitoring Program has been the emergence of the threat to biodiversity through elimination of diadromous species above dams, including in La Amistad and other protected areas.  For this and other reasons we have increasingly factored relation to proposed dam sites and the boundary of La Amistad into our site selection process.

Macroinvertebrates

Benthic Macroinvertebrate Surveys

FILO ARTHROPODA

Subfilo Crustacea

Clase Malacostraca

Subclase Eumalacostraca

Orden Decapoda

Familia Palaemonidae

Familia Atyidae

Orden Isopoda

Familia Asellidae

Orden Amphipoda

Familia Talitridae

Familia Gammaridae

Subfilo Atelocerata

Superclase Hexapoda

Clase Insecta

Subclase Pterygota

Orden Blattodea

Familia Blaberidae

Orden Coleoptera

Familia Psephenidae

Familia Ptilodactilidae

Familia Elmidae

Familia Hydrophilidae

Familia Limnychidae

Familia Lutochidae

Familia Lampiridae

Familia Gyrinidae

Familia Staphylinidae

gomphydea

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Familia Dryopidae

Familia Dytiscidae

Familia Hydraenidae

Familia Carabidae

Familia Chrysomelidae

Familia Curculionidae

Familia Haliplidae

Familia Scirtidae

Familia Noteridae

Orden Diptera

Familia Chironomidae

Familia Simulidae

Familia Tipulidae

Familia Tabanidae

Familia Blephariceridae

Familia Ceratopogonidae

Familia Psychodidae

Familia Culicidae

Familia Syrphidae

Familia Dixidae

Familia Dolichopodidae

Familia Empididae

gomphyde

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Familia Muscidae

Familia Stratiomyidae

Familia Athericidae

Familia Sciomyzidae

Orden Ephemeroptera

Familia Leptophlebiidae

Familia Leptohyphidae

Familia Heptageniidae

Familia Baetidae

Familia Oligoneuriidae

Familia Caenidae

Familia Euthyplociidae

Familia Polymitarcyidae

Familia Isonychiidae

Orden Hemiptera

Familia Naucoridae

Familia Notonectidae

Familia Nepidae

Familia Mesovellidae

Familia Vellidae

Familia Gerridae

Familia Belostomatidae

Familia Corixidae

Familia Pleidae

Orden Lepidoptera

Familia Pyralidae

Orden Odonata

Familia Gomphidae

Familia Libellulidae

Familia Coenagrionidae

Familia Megapodagrionidae

Familia Calopterygidae

Familia Lestidae

Familia Platysticidae

Familia Aeshnidae

Familia Polythoridae

Familia Perilestidae

Familia Protoneuridae

Familia Corduliidae

Familia Cordulegastridae

Orden Plecoptera

Familia Perlidae

coleoptera

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Orden Trichoptera

Familia Philopotamidae

Familia Hydropsychidae

Familia Polycentropodidae

Familia Hydrobiosidae

Familia Xiphocentronidae

Familia Glossosomatidae

Familia Hydroptilidae

Familia Helicopsychidae

Familia Leptoceridae

Familia Calamoceratidae

Familia Odontoceridae

Familia Ecnomidae

Familia Lepidostomatidae

Familia Limnephilidae

FILO MOLLUSCA

Clase Bivalvia

Orden Unionida

Clase Gastropoda

Subclase Prosobranchia

Orden Archeogastropoda

Familia Neritidae

Orden Mesogastropoda

Familia Ampullaridae

Familia Pilidae

Familia Hydrobiidae

Familia Valvatidae

Familia Bithyniidae

Familia Bythinellidae

Subclase Pulmonata

Orden Basommatophora

Familia Lymnaeidae

Familia Physidae

Familia Planorbidae

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FILO ANNELIDA

Clase Oligochaeta

Clase Hirudinea

Familia Glossiphonidae

Familia Hirudinae

Familia Erpobdellidae

FILO PLATYHELMINTHES

Clase Turbellaria

Orden Tricladida

Familia Planariidae

Fishes

Fish Surveys

To collect fish we use electrofishing equipment complemented with a variety of fishing nets.  Depending on the size and characteristics of a river, the team consists of between 3 and 9 people the majority are normally volunteers.  Volunteers are essential to the work we do not only in practical and economic term, but because including local volunteers is part of the biomonitoring project´s environmental education objective.  It usually takes three to four hours to complete a sample. Fish are identified by species, counted, examined for illnesses, parasites and other anomalies before being returned to the water.
Based on the results of the sample, we calculate a score, or Index of Biotic Integrity (IBI) for each site. According to the score,  complemented by the knowledge and professional judgement of ANAI staff, a bioclass rating is assigned (Excellent, Good, Fair, Poor and Very Poor). The lowest possible score is 12. A score of 60 (Excellent) corresponds to a river that has not been altered by humans. Key aspect of the information used to determine the Index of  Biotic Integrity include:

  • Number of native species found
  • Trophic level (place in the food chain) of the species encountered
  • Habitat  requirements (where species  live in the aquatic system)
  • Tolerance of contamination

Since 2008 we have also been involved in development of a Visual Index of Biotic Integrity (IBIVI), calculated on the basis of instream inventories, using facemask and snorkel. This method greatly facilitates participation and eventual “ownership” of the biomonitoring process by rural communities.

Development and refinement of fish-based biotic indices for Talamanca, and the humid tropics in general, is an open-ended process in which the ANAI team occupies a leadership position.  In 2010 we concluded that we had accumulated a sufficient body of data to permit a more rigorous statistical analysis of much of our data.  This is reflected in recently revised indices, but further improvement is to be expected.

Diadromy

As a consequence of our concerns about hydro dam proposals in the Greater Talamanca region diadromous animal (those obliged to move between marine and fresh water environments in order to complete their life cycles) have become a major focus of conservation concern  in Bocas del Toro and Talamanca.  An inescapable conclusion is that barriers to diadromous behavior would cause massive damage to ecosystems and fisheries anywhere in the region.  This in turn places the role of rivers and streams as altitudinal biological corridors in the spotlight.  We have been able to derive reliable estimates of the relative importance of diadromous fish and shrimp at different sites without recourse to full-scale quantitative sampling, such as is necessary for calculation of IBI.

For the foreseeable future much of our work will focus on diadromy and conservation of riverine corridors.

Benthic Macroinvertebrate Monitoring

Monitoring of benthic (bottom dwelling) macroinvertebrates, chiefly insects, is the most traditional method of stream biomonitoring, based on identifying samples of benthic organisms and applying indices similar to those described above for fish.  Staff and volunteers normally carry out macroinvertebrate samples at each site monitored, applying the BMWP-CR index which officially establishes criteria recognized by the government of Costa Rica.  For a more detailed account of our macroinvertebrate monitoring methods, see

We are also working to refine our macroinvertebrate assessment methodology to more closely correspond to the special characteristics of the Talamancan environment.  An important emphasis at this time is the study of diadromous shrimp, which constitute a major component of the macroinvertebrate assemblage in most of our streams, but are little studied.

Assessment of Habitat

Physical Habitat Assessment

The third component of our routine monitoring procedure is assessment of the quality of physical habitat at the site using a variant of the USDAStream Visual Assessment Protocol (SVAP)  adapted to the conditions of Talamanca.  SVAP is a user-friendly, extremely low-cost method which permits observers, after less than an hour of training, to derive an SVAP score, on a scale of 1 to 10 by analyzing factors such as

*Condition of the riparian vegetative buffer.

* Degree of sedimentation.

* Abundance and condition of habitat features such as pools and riffles

* Nearby sources of organic pollution

* Barriers to fish movement.