Topic
Codium
About: Codium is a research topic. Over the lifetime, 231 publications have been published within this topic receiving 5779 citations.
Papers published on a yearly basis
1 / 2
Papers
TL;DR: Increased water motion and retention of space by mussels in spring–summer would be effective in reducing the ability of C. fragile ssp.
Abstract: Summary
1
Artificial structures have become ubiquitous features of coastal landscapes. Although they provide novel habitats for the colonization of marine organisms, their role in facilitating biological invasions has been largely unexplored.
2
We investigated the distribution and dynamics of the introduced green alga, Codium fragile ssp. tomentosoides, at a variety of spatial scales on breakwaters in the north Adriatic Sea, and analysed experimentally the mechanisms underlying its establishment. We assessed the provision of sheltered habitats by breakwaters, the role of disturbance (e.g. from recreational harvesting and storms) acting at different times of the year, and the interactions between Codium and the dominant native space-occupier, the mussel Mytilus galloprovincialis.
3
Codium fragile ssp. tomentosoides has established viable populations on artificial structures along the shores investigated. The density, cover and size (length, branching and weight) of annual erect thalli of Codium was enhanced in sheltered conditions, resulting in the monopolization of landward low-shore habitats of breakwaters.
4
On the landward sides of breakwaters, disturbance enhanced recruitment of Codium. The time when bare space was provided within mussels beds was crucial. Removal of mussels in April or January did not affect the recruitment of Codium, whereas harvest in August, shortly before Codium gamete release, doubled its success. On the seaward sides of breakwaters, the effects of disturbance were more complex because mussels both inhibited recruitment of Codium and provided shelter from wave action to adult thalli.
5
Synthesis and applications. Artificial structures can provide suitable habitats for non-indigenous marine species and function as corridors for their expansion. Physical (wave exposure) and biotic (resident assemblages) features of artificial habitats can be important determinants of their susceptibility to biological invasions. Alternative options in the design of artificial structures and effective management of native assemblages could minimize their role in biological invasions. In particular, increased water motion and retention of space by mussels in spring–summer would be effective in reducing the ability of C. fragile ssp. tomentosoides to persist on the breakwaters investigated in this study.
334 citations
TL;DR: The mechanisms of seaweed introductions are little understood as research on introduced seaweeds has been mostly reactive, following discoveries of introductions and future research needs to elucidate the invasion process, interactions between invaders, and impacts to support prevention and management of seaweeds introductions.
Abstract: Introductions of non-indigenous species to new ecosystems are one of the major threats to biodiversity, ecosystem functions and services. Globally, species introductions may lead to biotic homogenisation, in synergy with other anthropogenic disturbances such as climate change and coastal pollution. Successful marine introductions depend on (1) presence of a transport vector, uptake of propagules and journey survival of the species; (2) suitable environmental conditions in the receiving habitat; and (3) biological traits of the invader to facilitate establishment. Knowledge has improved of the distribution, biology and ecology of high profile seaweed invaders, e.g. Caulerpa taxifolia, Codium fragile ssp. tomentosoides, Sargassum muticum, and Undaria pinnatifida. Limited, regional information is available for less conspicuous species. The mechanisms of seaweed introductions are little understood as research on introduced seaweeds has been mostly reactive, following discoveries of introductions. Sources of introductions mostly cannot be determined with certainty apart from those directly associated with aquaculture activities and few studies have addressed the sometimes serious ecological and economic impacts of seaweed introductions. Future research needs to elucidate the invasion process, interactions between invaders, and impacts of introductions to support prevention and management of seaweed introductions.
280 citations
TL;DR: Interactions among introduced species in New England kelp forests are examined to ask whether these interactions have altered paradigms describing subtidal communities in the Gulf of Maine and to result from one invasive species facilitating the spread of a second nonindigenous species.
Abstract: Ecological interactions among invading species are common and may often be important in facilitating invasions. Indeed, the presence of one nonindigenous species can act as an agent of disturbance that facilitates the invasion of a second species. However, most studies of nonindigenous species are anecdotal and do not provide substantive evidence that interactions among nonindigenous species have any community-level effects. Here, using a combination of field experiments and observations we examine interactions among introduced species in New England kelp forests and ask whether these interactions have altered paradigms describing subtidal communities in the Gulf of Maine. The green alga Codium fragile was observed at the Isles of Shoals, Maine, USA, in 1983 and has since replaced the native kelp as the dominant seaweed on leeward shores. Experiments manipulating kelp and Codium reveal that Codium does not directly inhibit growth or survival of kelp. Codium does, however, successfully recruit to gaps in the kelp bed and, once established, inhibits recruitment of kelp. A second nonindigenous species, Membranipora membranacea, grows epiphytically on kelp, and experiments reveal that the presence of Membranipora reduces growth and survival of kelp, resulting in defoliation of kelp plants and gap formation in kelp beds. In the absence of Codium, kelp recolonizes these gaps, but when present, Codium colonizes and prevents kelp recolonization. Manipulations of herbivores demonstrate that herbivory will reinforce Codium dominance. Thus, the demise of New England kelp beds appears to result from one invasive species facilitating the spread of a second nonindigenous species.
240 citations
154 citations
TL;DR: The results illustrate the importance of predator behavior and habitat context in modifying consumer pressure and community structure, and argue for the consideration of these factors in other multi-predator systems where habitats represent food and/or shelter.
Abstract: The high trophic connectivity of many communities can produce large numbers of indirect interactions. Although many trait-mediated indirect interactions (TMII) are caused by changes in prey behavior, less is known about the effects of changes in predator behavior such as prey switching or multiple predator effects (MPE) on indirect interactions, especially in marine systems. We performed a series of field caging experiments off the Isles of Shoals, Maine (USA) from 2000 to 2002 to test for the presence of behaviorally mediated indirect effects in a shallow subtidal food web. Specifically, crab (Cancer borealis) predation on sea urchins (Strongylocentrotus droebachiensis) was quantified in three habitats (Codium fragile algal beds, barrens, and mussel beds) representing differing combinations of food and shelter to examine the effects of prey switching by crabs. A second predator (the lobster, Homarus americanus) was added to the crab treatments to examine MPE effects.
Urchin mortality was significantly lower in the mussel habitat than in the Codium and barren habitats. Mussels produced a positive indirect effect on urchins by changing the behavior of crabs; crabs fed on mussels instead of urchins (prey switching). In the barrens, crab predation on urchins indirectly increased the abundance of the introduced ascidian, Diplosoma sp., whereas Codium density did not change among treatments.
A significant risk reduction for urchins occurred in Codium and barren habitats, but not in mussel habitats when crabs and lobsters were combined. Lobsters also produced a positive indirect effect on mussels by reducing crab predation. Thus, lobsters modify crab behavior and dampen changes in community structure.
Our results illustrate the importance of predator behavior and habitat context in modifying consumer pressure and community structure, and argue for the consideration of these factors in other multi-predator systems where habitats represent food and/or shelter.
142 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 9 |
| 2020 | 7 |
| 2019 | 3 |
| 2018 | 6 |
| 2017 | 3 |
| 2016 | 4 |