{"title":"Relative size matters: Spawning substrate roughness size and spacing affect egg dislodgement and retention in the benthos","authors":"Jake Carman, Yingming Zhao, Josef D. Ackerman","doi":"10.1002/lno.12715","DOIUrl":null,"url":null,"abstract":"The consequences of hydrodynamic effects on survival of embryonic benthic organisms remain unknown. This is because the interaction of hydrodynamics and substrate roughness is complex, but it can be conceptualized in two dimensions by roughness flow regimes (isolated, wake interference, and skimming flow) or roughness types (<jats:italic>k</jats:italic>‐ and <jats:italic>d</jats:italic>‐type). We examined the effect of different roughness flow regimes/roughness types and roughness heights (<jats:italic>k</jats:italic>) on the dislodgement of walleye (<jats:italic>Sander vitreus</jats:italic>) eggs (2 mm diameter, ⌀) using a wall jet apparatus. We expected that lower wall shear stress (<jats:italic>τ</jats:italic><jats:sub>w</jats:sub>) would be required for dislodgement in more‐exposed/less‐sheltered roughness type/flow regimes (i.e., <jats:italic>k</jats:italic>‐type/isolated roughness flow) and when <jats:italic>k</jats:italic> ≤ ⌀. Surprisingly, the opposite was found, indicating that other mechanism(s) are also responsible for egg dislodgement on these rough surfaces. Hydrodynamic sheltering occurred when flow was directed over exposed eggs (<jats:italic>k</jats:italic> ≤ ⌀) adjacent to roughness elements effectively increasing their width, and thus requiring higher <jats:italic>τ</jats:italic><jats:sub>w</jats:sub> for rolling and then ejection. When <jats:italic>k</jats:italic> > ⌀, eggs dislodgement likely occurred via the lower pressure in the eddies recirculating in the groove width between roughness elements, rather than due to <jats:italic>τ</jats:italic><jats:sub>w</jats:sub>. These results indicate the relevance of heterogeneous sorting and sizing of substrate elements to provide suitable spawning habitats in benthic environments.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"10 1","pages":""},"PeriodicalIF":3.8000,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Limnology and Oceanography","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1002/lno.12715","RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"LIMNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The consequences of hydrodynamic effects on survival of embryonic benthic organisms remain unknown. This is because the interaction of hydrodynamics and substrate roughness is complex, but it can be conceptualized in two dimensions by roughness flow regimes (isolated, wake interference, and skimming flow) or roughness types (k‐ and d‐type). We examined the effect of different roughness flow regimes/roughness types and roughness heights (k) on the dislodgement of walleye (Sander vitreus) eggs (2 mm diameter, ⌀) using a wall jet apparatus. We expected that lower wall shear stress (τw) would be required for dislodgement in more‐exposed/less‐sheltered roughness type/flow regimes (i.e., k‐type/isolated roughness flow) and when k ≤ ⌀. Surprisingly, the opposite was found, indicating that other mechanism(s) are also responsible for egg dislodgement on these rough surfaces. Hydrodynamic sheltering occurred when flow was directed over exposed eggs (k ≤ ⌀) adjacent to roughness elements effectively increasing their width, and thus requiring higher τw for rolling and then ejection. When k > ⌀, eggs dislodgement likely occurred via the lower pressure in the eddies recirculating in the groove width between roughness elements, rather than due to τw. These results indicate the relevance of heterogeneous sorting and sizing of substrate elements to provide suitable spawning habitats in benthic environments.
期刊介绍:
Limnology and Oceanography (L&O; print ISSN 0024-3590, online ISSN 1939-5590) publishes original articles, including scholarly reviews, about all aspects of limnology and oceanography. The journal''s unifying theme is the understanding of aquatic systems. Submissions are judged on the originality of their data, interpretations, and ideas, and on the degree to which they can be generalized beyond the particular aquatic system examined. Laboratory and modeling studies must demonstrate relevance to field environments; typically this means that they are bolstered by substantial "real-world" data. Few purely theoretical or purely empirical papers are accepted for review.