Short-Term Disturbance Effects of Outdoor Education Stream Classes on Aquatic Macroinvertebrates

Abstract

Outdoor education programs frequently offer stream classes that teach students how to assess water quality based on the composition of aquatic macroinvertebrate communities. Repeatedly using the same site for stream classes can cause disturbance that could negatively impact aquatic macroinvertebrates. However, the impact of outdoor education stream classes on short term temporal trends of aquatic macroinvertebrates has not been evaluated. Our objective was to quantify whether outdoor education stream classes caused localized and short-term impacts on the aquatic macroinvertebrate community. We sampled aquatic macroinvertebrates over a five day period in May 2014 from an impacted riffle subjected to repeated substrate disturbance by outdoor education stream classes and an unimpacted riffle that was not subjected to stream classes within an agricultural stream in central Ohio. We did not observe a difference in macroinvertebrate community response variables between different time periods or among days within the impacted riffle as part of our within riffle analysis. We documented that macroinvertebrate abundance and dorsoventrally flattened clinger abundance was greater within the unimpacted riffle than the impacted riffle. Macroinvertebrate evenness was greater in the impacted riffle than the unimpacted riffle. In the impacted riffle percent clingers was greater on Monday than on Friday. Conversely, in the unimpacted riffle percent clingers was greater on Friday than on Monday. Our results indicated that outdoor education stream classes did not alter short term temporal trends of macroinvertebrate community structure within an impacted riffle, but the stream classes resulted in differences in community structure between an impacted and unimpacted riffle. Our results suggest that outdoor

Effects of Student-Induced Trampling on Aquatic Macroinvertebrates in Agricultural Headwater Streams

“…Given that the flow within the streams was low and similar to the still water in the sorting pans, we assumed that macroinvertebrates released into the stream after identification would also attach to the nearest substrate. Additionally, based on our previous findings [25] we anticipated that if our repeated sampling of the same plots biased our results, then we would have observed consistent daily reductions in all macroinvertebrate community response variables except evenness. This was not the case as some macroinvertebrate response variables increased as the experiment progressed, other response variables decreased and some did not change.…”

“…It is also possible that repeated sampling of fixed plots within the riffles may have caused sampling related bias, which resulted in our observation of spatial and temporal differences in macroinvertebrate communities but not an effect of the experimental disturbance. We chose to sample the same plots repeatedly because our previous experience with sampling macroinvertebrates within riffles of streams in central Ohio indicated considerable within riffle variability in macroinvertebrate community structure [25]. Thus, we believed repeatedly sampling the same plots within the riffles would help account for the anticipated within riffle variability and increase the likelihood of observing an effect of our experimental disturbance.…”

“…The effect of repeatedly using riffles within agricultural headwater streams for stream classes has not been evaluated and needs to be addressed in future research studies. The majority of the research evaluating the effects of repeated trampling on stream macroinvertebrates in larger streams indicates that trampling can negatively impact aquatic macroinvertebrates but post-trampling recovery can occur quickly [13][14][15][16][17][18]25,26]. In light of these findings we recommend that educational organizations that repeatedly use agricultural headwater streams for stream classes adopt precautionary measures such as rotating their usage of class sites to enable the macroinvertebrates to recover from trampling by students.…”

“…In contrast, day-use nature centers, parks and camps that host multi-day OE programs often serve large numbers of students each year and may conduct stream classes regularly throughout the year within the same site. Such high use programs conducted at the same site have been shown to negatively impact macroinvertebrate abundance, taxa richness, EPT (Ephemeroptera, Plecoptera, Trichoptera) abundance and clinger abundance and cause greater movement of streambed substrate in a fourth order stream in central Ohio [25,26]. During conditions of elevated discharge OE stream classes may be cancelled or relocated to small headwater streams to avoid unsafe conditions [26].…”

“…Our aim was to document the short-term responses of macroinvertebrates to an experimental simulation of trampling by students that results from conducting OE stream classes within small headwater streams. This study was one of four studies conducted at multiple spatial and temporal scales from 2013 to 2015 to quantify the influence of OE stream classes on aquatic macroinvertebrates [25][26][27]. We hypothesized that within headwater streams in central Ohio a pulse disturbance simulating the impacts of student-induced trampling will cause an immediate negative impact on the macroinvertebrate community in experimentally disturbed riffles followed by a rapid recovery trend, while no disturbance-related changes in community structure will occur in control riffles.…”