The longnose dace (Rhinichthys cataractae) is found in muddy and warm, clear and cold, streams and lakes. The largest longnose dace are about 6 inches long. They are well-adapted for living on the bottom of fast-flowing streams among the stones. Longnose dace eat mostly immature aquatic insects. They are important forage minnows for larger predatory fish. Introduction The longnose dace and the monitoring plan for this species will be the subject of this paper. The first step in the monitoring plan will be to collect data to establish baseline data for the longnose dace and its habitat requirements and the current state of the area of study. The second phase of the plan will be to ascertain if the planned projects were carried out as they were intended. This is known as implementation monitoring. Then once a baseline of data has been established and conformation that the monitoring plan has been implemented as intended, anticipated results and outcomes can be evaluated. This is known as effectiveness monitoring. During this stage sampling will be completed to verify that the plan is achieving the expected results. This will be followed by validation monitoring to ascertain if the plan is working as designed or if it needs to be adjusted to better establish a more complete monitoring plan (Karsian 2002). The longnose dace is located from coast to coast, south to the Rocky Mountains into Mexico, north to the Arctic circle, and into the southern Appalachian Mountains (Leo 2012). Longnose dace are well adapted to feeding on the bottom and are generalists. They will eat a wide variety of aquatic insects and as fry they consume mainly algae. Mainly occur in swift flowing riffles on a steep gradient with gravel and rock bottoms. Longnose dace reach reproductive age a two years of age with a maximum life span of ten years. Spawning occurs when water temperatures reach 15 degrees C. Spawning occurs in riffles with a substrate that allows for the formation of natural depressions.(Edwards et al 1983). Longnose dace are a species of least concern and there are no current management plans being implemented. Management recommendations are to limit relocation of the species to prevent hybridization with Rhinicthys osoculus (Leo 2012).
GEOGRAPHIC DISTRIBUTION
The native range of the longnose dace hasn’t been greatly affected by the actions of man and is generally found above 40 N and from coast to coast. It is one of the most widely dispersed forage fish in the United States and is also found in Canada. They are distributed throughout the continental United States with their range reaching as far south as the Rockie Mountains in northern Mexico and as far north as the Arctic Circle. The habitat for the longnose dace varies from the inshore waters of the Great Lakes to small mountain streams in the Smokey Mountains. It has been introduced into the waters of the Colorado River in Colorado, the Ohio River drainage in Kentucky, the upper Roanoke drainage in Virginia, along with sites in the upper Green River drainage in Wyoming, and various sites in Utah (Nico 2012).
ECOLOGY
Longnose dace are generally found in moderately cool water streams with temperatures up to 22 degrees C. They tend to be benthic and inhabit area just above the substrate. They prefer the riffle areas in streams on steep gradients, that have gravel and rock beds but in the absence of competing species they will occupy shallow pools (Edwards et. Al 1983). The longnose dace is preyed upon a multitude of species including to but not limited to smallmouth bass (micropterus dolomieu), rockbass (Ambloplites rupestris), rainbow trout (Oncorhynchus mykiss), and brown trout (Salmo truta) and fish-eating birds. It is mainly a bottom feeder with the majority of its diet as an adult, up to 90%, being adult or immature simulids, chironomids, and ephemerids (Goldstien and Simon 1999). Algae compromises the majority of the diet longnose dace under the length of 49mm (Gerald 1966). Heavy siltation would have a negative effect due to the fact that it would cover the rock and gravel bed of the stream. Deforestation could also have a negative effect on the longnose dace because the lack of tree cover would raise the water temperatures to a level that that couldn’t sustain them.
LIFE HISTORY
Longnose dace typically have a lifespan of no more than 5 years with the average being 3 years. They have a polygynandrous mating system and become reproductively viable at 1 year of age. Spawning usually occurs in the summer and females are capable of spawning up to 6 times during that time period. Males are territorial and breed with females that come into their territory. Clutches range in size from 1100 to 2500 eggs with larva hatching 3 to 4 days after fertilization. Spawning occurs in the temperature range of 14 to 19 degrees C and over a gravel bed and a broadcasting method. There is no parental care giving to the young and become pelagic after 9 to 12 days (Duby 2012). Humans can influence reproduction by allowing excessive siltation to enter the stream or river covering the gravel beds.
CURRENT MANAGEMENT
The longnose dace is a species of least concern and there are no species-specific conservation and/or management plans currently being implemented. Management of other species such as the brook trout (Salvelinus fontinalis) have a positive effect on the longnose dace as well by preserving the habitat of the brook trout through proper management, promotes a healthy and productive habitat for the longnose dace as well. Longnose dace can be used as an indicator species for water bodies that have been negatively impacted by human activities. A reduction of numbers in this species often indicates that the biological integrity of the stream has been compromised. As with many other fish species siltation can lead to a decline in numbers and the overall viability of the species. Agricultural runoff, deforestation, and rising water temperatures can also play a major role in the decline, extirpation, and or extinction of a species. These factors must be limited or completely curtailed in order for the longnose dace to continue its current path of successfulness.
MANAGEMENT RECOMMENDATIONS
The monitoring of the longnose dace should be done on an annual basis. Survey sites should be established on streams, rivers, and in lake systems that have known populations. Survey sites should also be established in areas where the longnose dace has been introduced and in areas where the long nose dace isn’t present but where the local habitat is suitable for the fish. These sites should be one hundred meters in length for the streams and rivers. Block nets should be used, when viable, at the beginning and ending of each site to prevent fish in the survey area escaping and new fish entering the site. On larger bodies of water the use of block nets would not be practical. The fish would be sampled using electro fishing. In the lake systems where the longnose dace is present the fish would be sampled with minnow traps and with fine mesh trap nets. The traps would be placed in areas within the lake that are suitable for the fish. Size, weight, and numbers of the fish should be recorded to establish a base line of data that can be compared with data collected in following surveys. The removal of the longnose dace from areas where it has been introduced should be of priority to keep the fish from hybridizing with the native species. Electro fishing should be used to remove as many of the native fish as possible and placed in areas that aren’t going to be slated for restoration. Rotenone or antimycin should be used to remove the remaining fish and then the native fish should be restocked into the bodies of water. Taking into consideration the current state of the longnose dace no specific management plan needs to be implemented. The continued monitoring of the population would be the only recommendation for this species.