Importance of Floodplain Connectivity to Fish Populations in the Apalachicola River, Florida

Abstract

Floodplain habitats provide critical spawning and rearing habitats for many large‐river fishes. The paradigm that floodplains are essential habitats is often a key reason for restoring altered rivers to natural flow regimes. However, few studies have documented spatial and temporal utilization of floodplain habitats by adult fish of sport or commercial management interest or assessed obligatory access to floodplain habitats for species' persistence. In this study, we applied telemetry techniques to examine adult fish movements between floodplain and mainstem habitats, paired with intensive light trap sampling of larval fish in these same habitats, to assess the relationships between riverine flows and fish movement and spawning patterns in restored and unmodified floodplain distributaries of the Apalachicola River, Florida. Our intent is to inform resource managers on the relationships between the timing, magnitude and duration of flow events and fish spawning as part of river management actions. Our results demonstrate spawning by all study species in floodplain and mainstem river habitat types, apparent migratory movements of some species between these habitats, and distinct spawning events for each study species on the basis of fish movement patterns and light trap catches. Additionally, Micropterus spp., Lepomis spp. and, to a lesser degree, Minytrema melanops used floodplain channel habitat that was experimentally reconnected to the mainstem within a few weeks of completing the restoration. This result is of interest to managers assessing restoration activities to reconnect these habitats as part of riverine restoration programmes globally. Copyright © 2012 John Wiley & Sons, Ltd.

Comparative use of side and main channels by small‐bodied fish in a large, unimpounded river

“…We speculate that multiple mechanisms may interact to support fish abundances and diverse assemblages in complex channels of the Yellowstone River. First, side channels may offer high quality spawning (Burgess, Pine & Walsh, ) and nursery (Copp, ; Adams et al ., ) grounds, especially for fishes that broadcast demersal, adhesive eggs (e.g., sand shiners; Platania & Altenbach, ). Additionally, the ichthyoplankton of broadcast spawners with non‐adhesive eggs, such as western silvery minnows (Layher, ), flathead chub (Durham & Wilde, ), and emerald shiners (Becker, ), may drift into side channels during runoff, develop in the relatively slack waters of side channels, and subsequently migrate towards the main channel as seasonally inundated side channels dewater.…”

Otolith chemistry as a fisheries management tool after flooding: The case of Missouri River gizzard shad

“…Fish production is highly influenced by river–floodplain connectivity, generally increasing with connectivity due to greater primary production, spawning and nursery habitat coverage, and prey availability (Agostinho & Zalewski, ). Events that sever or reduce connectivity (e.g., sedimentation after floods) can disrupt spawning, rearing, and foraging resources and reduce fish production with negative ecological and socioeconomic consequences for fisheries (Burgess, Pine, & Walsh, ).…”

Predicting Floodplain Hypoxia in the Atchafalaya River, Louisiana, USA, a Large, Regulated Southern Floodplain River System

“…The river/floodplain connection created with the advance of the annual flood pulse can greatly enhance the diversity and productivity of both riverine and floodplain flora and fauna by providing nutrient import and export (Robertson et al , ; Amoros and Bornette, ; Burgess et al , ) and access to floodplain spawning and nursery areas (Ward and Stanford, ; Galat et al , ; Górski et al , ; but refer to Humphries et al , ). However, rising waters can also significantly reduce floodplain dissolved oxygen (DO) levels because of bacterial consumption of dissolved organic carbon from terrestrially derived organic matter in inundated riparian habitats (Baldwin, ; Whitworth et al , ).…”