Dam,Elevation,Gage #,Observations
Carite,543.6,39990,Greathouse (2005) and Greathouse et al. (in press) primarily examined high-gradient, high-elevation streams above waterfalls with a goal of comparing sites above dams that fit the "no regular spillway discharge" category to sites with no large dams.  Sampling included electroshocking and standardized snorkeling for shrimp and fish abundances (see Greathouse 2005 for details on study sites and methods).  During the course of field work for Greathouse (2005) and Greathouse et al. (in press), we unexpectedly observed rare occurrences of migratory shrimps and fishes at 3 sites above dams.  One of these sites (Greathouse 2005 site code: D1) was above the Carite Reservoir.  During electroshocking of 6 pools and 6 riffles in site D1, 3 Xiphocaris shrimps were collected from a single pool.  In this pool, we counted an additional 13 Xiphocaris occurring outside of our electroshocked area.  We did not capture during electroshocking or record during standardized snorkeling observations any other native fishes or shrimps at Carite or at any other of our dammed survey sites.  However, during the course of our field work and study site selection, we did visually observe additional migratory fauna at Carite and other dammed sites.  At Carite, we observed four Gobiomorus dormitor occurring in three pools.  The Xiphocaris we observed at Carite had long rostrums which are typical of younger shrimp occurring in low-elevation streams containing predatory fishes (such as G. dormitor) (Villamil and Clements 1976); long rostrums may be a morphological defense against predatory fishes (J. March, Washington and Jefferson College, personal communication).
Comerio,144.78,44100,Unpublished data from Holmquist et al. (1998): mean number of native shrimps and fishes occurring in electroshocking samples above the La Plata and Comerio dams = 13 individuals/100-sec. shocking sample
Guayabal,100.89,111300,Unpublished data from Holmquist et al. (1998): mean number of native shrimps and fishes occurring in electroshocking samples above the Guayabal Reservoir= 41 individuals/100-sec. shocking sample
Coamo,48.77,106850,We have not attempted to make observations on or sample for migratory shrimps and fishes above this dam, and to our knowledge, no other researchers have attempted to make observations.
Patillas,58.22,93045,Observations of migratory shrimps and fishes are described/reported in previously published studies.
Guajataca,196.9,10800,Observations of migratory shrimps and fishes are described/reported in previously published studies.
El Guineo,,,E. Greathouse visually observed a low abundance of Xiphocaris shrimps on 16 July 2002 in a stream above the El Guineo reservoir (at ~18 degrees 9' 44.36" N, 66 degrees 31' 49.98" W).
Matrullas,,,Observations of migratory shrimps and fishes are described/reported in previously published studies.
Dos Bocas,89.9,27100,Following a natural spillway discharge event associated with Hurricane Hortense in 1996, targeted sampling for shrimps and fishes above the Dos Bocas Reservoir yielded low abundances of juvenile Macrobrachium, atyids, and Xiphocaris (J. Holmquist, personal observation/unpublished data).  Prior to the spillway discharge, there were significant numbers of native fauna below the Dos Bocas dam but none above the structure.  Immediately after the hurricane, several shrimps were captured in the reservoir (non-quantitative sampling because of lack of flow).  A small number of shrimps were also collected in the three rivers that flow into the reservoir (mean number of shirmps captured= 1.0 per 100 sec. shocking time).  These animals were all juveniles and were two Macrobrachium faustinum (carapace length: 3.28 and 3.13 mm), one Xiphocaris elongata (carapace length: 5.84 mm), and one Atya sp. (carapace length: 4.65 mm).  At least one shrimp was found in each of the three rivers.  Two months later, river sampling again yielded 1 shrimp per 100 sec. shocking time, but all individuals were from the Lim¢n River and were 4 Atya scabra (carapace length: 9.12, 8.72, 8.63, and 7.38 mm).  Sampling four, six, and eight months after the storm failed to yield any native fauna.  Collections following two other, shorter releases in 1997 yielded no native fauna.
Garzas,,,Observations of migratory shrimps and fishes are described/reported in previously published studies.
Las Curias,,,We have not attempted to make observations on or sample for migratory shrimps and fishes above this dam, and to our knowledge, no other researchers have attempted to make observations.
Cidra,402.94,47550,Observations of migratory shrimps and fishes are described/reported in previously published studies.
Caonillas,251.8,26140,Observations of migratory shrimps and fishes are described/reported in previously published studies.
Adjuntas,379.48,20550,Observations of migratory shrimps and fishes are described/reported in previously published studies.
Pellejas,336.8,,no gage; We have not attempted to make observations on or sample for migratory shrimps and fishes above this dam, and to our knowledge, no other researchers have attempted to make observations.
Vivi,324.61,23110,We have not attempted to make observations on or sample for migratory shrimps and fishes above this dam, and to our knowledge, no other researchers have attempted to make observations.
Loco,70.1,128900,Unpublished data from Holmquist et al. (1998): mean number of native shrimps and fishes occurring in electroshocking samples above the Loco Reservoir= 310 individuals/100-sec. shocking sample
Luchetti,173.7,125480,Greathouse (2005) and Greathouse et al. (in press) primarily examined high-gradient, high-elevation streams above waterfalls with a goal of comparing sites above dams that fit the "no regular spillway discharge" category to sites with no large dams.  Sampling included electroshocking and standardized snorkeling for shrimp and fish abundances (see Greathouse 2005 for details on study sites and methods).  During the course of field work for Greathouse (2005) and Greathouse et al. (in press), we unexpectedly observed rare occurrences of migratory shrimps and fishes at 3 sites above dams.  One of these sites was above the Luchetti Reservoir.  On 30 June 2002, we observed shrimps at a site located above the Luchetti Reservoir (Greathouse 2005 site code: D15, location: 18 degrees 5' 49.57" N, 66 degrees 50' 59.17" W).  The site was running dry (i.e., intermittent/temporary), with only ~100 m of the stream bed containing a series of isolated pools and riffles.  Just upstream from the road crossing, in a single pool (surface area: ~5 m2, depth: ~0.8 m), we observed large atyid and Xiphocaris shrimps at high densities which were visually similar to the shrimp densities we observed at similar undammed sites.  The other isolated riffles and pools were very shallow, and outside of this 100-m reach, the stream bed was dry for the full extent that we hiked (~500 m upstream and ~300 m downstream).  During a return visit to this site on 16 February 2003, physical and biotic conditions, including shrimp abundances, were similar to conditions in June 2002.  The high density of shrimps in the isolated pool of the temporary stream above the Luchetti reservoir may represent low shrimp densities becoming concentrated as a stream dries, the reverse trend of apparent dispersal by shrimps above the Dos Bocas Reservoir following Hurricane Hortense (see Dos Bocas observations).
Loiza,31,59000,On July 31, 2002, E. Greathouse observed 2 Xiphocaris shrimps at the Road 948 bridge crossing R¡o Gurabo (18 degrees 15' 1.83" N, 65 degrees 49' 48.51" W).  Observations of migratory shrimps and fishes are also described/reported in previously published studies.
Prieto,452.63,142500,On May 11, 2003, in an unnamed tributary of R¡o Prieto, E. Greathouse visually observed 3 atyids where Road 428 crosses the tributary, north of Hacienda Fortuna (18 degrees 9' 43.27" N, 66 degrees 51' 40.82" W).
Guayo,445,141500,On May 16, 2003, in an unnamed tributary of the Guayo Reservoir, E. Greathouse visually observed at least 2 Xiphocaris and 3 atyid shrimps in the northern branch of the tributary where it is crossed by Road 135 (18 degrees 11' 4.67" N, 66 degrees 50' 42.21" W).
Yahuecas,448.36,141100,On May 11, 2003, in a tributary of R¡o Yahuecas crossed by a road off of Road 525 near the University of Puerto Rico's agricultural experiment station, E. Greathouse visually observed atyid shrimps.
Toa Vaca,154.8,111210,Greathouse (2005) and Greathouse et al. (in press) primarily examined high-gradient, high-elevation streams above waterfalls with a goal of comparing sites above dams that fit the "no regular spillway discharge" category to sites with no large dams.  Sampling included electroshocking and standardized snorkeling for shrimp and fish abundances (see Greathouse 2005 for details on study sites and methods).  During the course of field work for Greathouse (2005) and Greathouse et al. (in press), we unexpectedly observed rare occurrences of migratory shrimps and fishes at 3 sites above dams.  One of these sites was above the Toa Vaca Reservoir.  In summer 2002 at our stream site above the Toa Vaca Reservoir (Greathouse 2005 site code: D6), we observed one Xiphocaris shrimp in a single pool on four different occasions and three Xiphocaris in a second pool on one occasion (over the course of a 6-week experiment involving day and night visits to the site every few days).  Normal densities of Xiphocaris shrimps in similar pools of undammed sites are hundreds to thousands per pool (E. Greathouse, unpublished data).
La Plata,47.12,45000,Unpublished data from Holmquist et al. (1998): mean number of native shrimps and fishes occurring in electroshocking samples above the La Plata and Comerio dams = 13 individuals/100-sec. shocking sample
Cerrillos,186.3,113950,After construction of the Cerrillos in 1992, large and presumably old atyid shrimps and Sicydium gobies still occurred upstream after eight (J. Holmquist, personal observation: atyids and Sicydium observed) and 11 (E. Greathouse, personal observation: 1 atyid seen in a stream pool in 2003) years.
Portugues,,,Uknown elevation; no gage; We have not attempted to make observations on or sample for migratory shrimps and fishes above this dam during construction, and to our knowledge, no other researchers have attempted to make observations during construction.