The effect of salinity on aspects of the early development of the kelp species Undaria pinnatifida and Saccorhiza polyschides

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Victoria M. Crane ◽  
Marie-Fanny Racault ◽  
Robert L. Fletcher
Keyword(s):  
Native Species ◽  
Life Histories ◽  
Full Range ◽  
Salinity Range ◽  
Subtidal Zone ◽  
Female Ratio ◽  
Blade Length ◽  
The North ◽  
Saccorhiza Polyschides ◽  
Sporophyte Production

Abstract It is likely that the introduction of the brown macroalga Undaria pinnatfida from the Pacific into the North Atlantic will impact competitively on the native species Saccorhiza polyschides; both are large kelps occupying the same subtidal zone with very similar life histories. The present study examines their tolerance to changes in salinity, under laboratory conditions, in order to provide a better understanding of their respective competitiveness in an estuarine environment. Experiments were carried out over a full range of salinity values, from 35 to 0, with respect to zoospore settlement and attachment, germination, post-germination progression to form gametophytes, gametophyte sex ratio, sporophyte production and blade length. Undaria zoospores settled and attached over the salinity range from 35 to 14 and germinated between 35 and 3.5. Post-germination progression occurred over the range from 35 to 14 whilst only small differences in the male/female ratio were recorded. Sporophyte blade production and development occurred over the range from 35 to 17.5 and peak production and longest blade length was recorded at 21. Saccorhiza zoospores settled and attached at and above 24.5 and germinated between 35 and 21. Sporophyte production and blade development occurred over the range from 35 to 24.5. In general, Undaria was shown to be much more tolerant of reductions in salinity compared to Saccorhiza and is more likely to penetrate further into estuarine environments.

scholarly journals Rasprostranjenost nezavičajne vrste kamenice Magallana gigas(Thunberg, 1793) duž istočne obale Jadrana

2019 ◽  
Vol 60 (2) ◽  
pp. 137-146 ◽  
Author(s):  
Daria Ezgeta-Balić ◽  
Tanja Šegvić-Bubić ◽  
Elizabeta Briski ◽  
Leon Grubišić ◽  
Dubravka Bojanić Varezić ◽  
...  
Keyword(s):  
Native Species ◽  
Littoral Zone ◽  
Adriatic Sea ◽  
Invasion Success ◽  
Subtidal Zone ◽  
Anthropogenic Habitats ◽  
The North ◽  
North Eastern ◽  
Zone Ii ◽  
The 1960S

Non-native Pacific oyster Magallana gigas (Thunberg, 1793) was introduced to the Mediter-ranean Sea for aquaculture purposes in the 1960s. Although this species was not introduced for aquaculture to the Croatian part of the Adriatic Sea, in the 1970s, it was reported in the Lim Bay, in the North-eastern Adriatic. Until recently, there has been no research on the species in the Croatian part of the Adriatic. The aim of this research was to summarize existing and novel data on the distribution of M. gigas in coastal areas of the Eastern Adriatic and to provide a baseline for the future monitoring and assessment programmes of the species. Distribution of M. gigas was determined by three different methods: (i) a visual census of the presence of M. gigas specimens in the medio-littoral zone; (ii) DNA identification of M. gigas larvae in the water column; and (iii) the presence of M. gigas in the subtidal zone at depth between 25 and 40 m. Magallana gigas has a well-established population in the medio-littoral zone of natural and anthropogenic habitats along the coast of the North-eastern Adriatic Sea (west coast of Istria peninsula), but it is not present in the deeper layers . In the Central-eastern and South-eastern Adriatic Sea, the species was either absent or sporadically recorded with no evidence of fully established populations. Considering the great invasion success of M. gigas worldwide and effects that this species could have on the invaded ecosystem (e.g. competition for food and space with native species), detailed future monitoring is needed for the Eastern Adriatic Sea.

Modeling of ecological conditions in the Euxine Basin in the Sarmatian and Maeotian by methods of diatom analysis

2019 ◽  
pp. 257-261
Author(s):  
Eleonora P. Radionova
Keyword(s):  
Black Sea ◽  
Late Miocene ◽  
The Black Sea ◽  
Subtidal Zone ◽  
Diatom Analysis ◽  
Diatom Flora ◽  
North West ◽  
Ecological Conditions ◽  
The North

The associations and ecological conditions of the existence of modern diatoms of the North-West (Pridneprovsky), Prikerchensky and Eastern regions of the subtidal zone of the Black Sea are considered. Based on the unity of the composition of the Present and Sarmatian-Meotian diatom flora, an attempt has been made to model some of the ecological c situation of the Late Miocene Euxinian basin.

Forest ecological restoration using native species in the North-West of Tunisia: a brand new experience of participatory approach.

2019 ◽  
Vol 45 (1) ◽  
pp. 75-84
Author(s):  
Issam Touhami ◽  
Ali El khorchani ◽  
Zouheir Nasr ◽  
Mohamed tahar Elaieb ◽  
Touhami Rzigui ◽  
...  
Keyword(s):  
Ecological Restoration ◽  
Native Species ◽  
Participatory Approach ◽  
North West ◽  
The North

scholarly journals Reproductive phenology of the American Bullfrog in subtropical Brazil: photoperiod as a main determinant of seasonal activity

2016 ◽  
Vol 88 (3 suppl) ◽  
pp. 1909-1921 ◽  
Author(s):  
CAMILA I. MEDEIROS ◽  
CAMILA BOTH ◽  
IGOR L. KAEFER ◽  
SONIA Z. CECHIN
Keyword(s):  
Life Histories ◽  
Management Strategies ◽  
Reproductive Activity ◽  
Ex Situ ◽  
Reproductive Phenology ◽  
High Fertility ◽  
Seasonal Activity ◽  
Population Declines ◽  
American Bullfrog ◽  
The North

ABSTRACT The North American bullfrog Lithobates catesbeianus continues to invade ecosystems worldwide, potentially causing population declines and even extinctions. Within its native distribution, bullfrogs show prolonged reproductive seasons and high fertility. However, data on breeding biology of bullfrogs ex-situ in invaded localities mainly comes from anecdotal reports. Understanding how invasive species are adjusting their life histories to new colonized environments is important for conservation purposes. Here we describe temporal and spatial abundance, calling activity, spawning and tadpole distribution of bullfrogs in southern Brazil. Eighteen samplings occurred during one year. The abundance of individuals was positively related to longer photoperiods and higher temperatures. Reproductive activity was also positively associated with longer photoperiods. Calling sites, spawning and tadpoles were associated with microhabitats presenting hydrophytes, which may provide shelter and thermal stability to bullfrogs. The reproductive seasonal activity of bullfrogs can be highly variable across its growing geographical range, but in subtropical Brazil it is associated with photoperiod, a highly predictable abiotic determinant. In our study area, bullfrogs presented a breeding season twice as long as that observed in some native localities. We suggest that management strategies directed to bullfrog populations must consider the habitat structures and seasonal regimes determined by each invaded environment.

scholarly journals Fish Assemblage in the Euphrates River at Al-Samawa City, Southern Iraq

2019 ◽  
Vol 32 ◽  
pp. 33-46
Author(s):  
Ammar M.S. Al-Helli ◽  
Amjad K. Resen ◽  
Atheer H. Ali
Keyword(s):  
Native Species ◽  
Ecological Factors ◽  
Abundant Species ◽  
Total Hardness ◽  
Dominance Index ◽  
Oreochromis Aureus ◽  
Euphrates River ◽  
The North ◽  
Blue Tilapia ◽  
Southern Iraq

The study was conducted in the Euphrates river in Al-Samawa city at two stations during the period from October 2016 till September 2017. The first station (north station) was Al-Majd township (45°12'49.2"E, 31°22'14.9"N), and the second station (south station) was Al-Zaier region (45°20'21.4"E, 31°18'54.4"N). Some ecological factors were monthly recorded at the stations of the current study, including water temperature, salinity, dissolved oxygen, pH, transparency, the speed of water flow, BOD5 and total hardness. All factors except total hardness have not significant differences between two stations, The hardness in the north station showed higher (844-1475) mg.l-1 than south station (655-1250) mg.l-1. Fishes were collected by gill nets, cast net, hook and line, hand net and electro-fishing. A total of 4260 fish specimens were collected which belong to 24 species and 10 families, 17 species of them were native species whereas seven of them were alien species. The most abundant species was blue tilapia Oreochromis aureus constituted 26.84% of the total caught of a north station, The value of the dominance index (D3) in north station was 62.57%, while the most abundant species in south station was Prussian carp Carassius auratus constituted 27.14% of the total caught, The value of the dominance index (D3) in the south station was 56.42%.

Historical Changes in Large River Fish Assemblages of the Americas

2005 ◽  
Keyword(s):  
Native Species ◽  
Fish Assemblages ◽  
Fish Fauna ◽  
Large River ◽  
Platte River ◽  
Water Diversions ◽  
The North ◽  
As Species ◽  
South Platte ◽  
The City

<em>Abstract.</em>—From its headwaters in the Rocky Mountains, the Platte River drains 230,362 km<sup>2</sup> in Colorado, Wyoming, and Nebraska. The Platte River is formed by the confluence of the North Platte and South Platte near the city of North Platte, Nebraska, and receives additional flow from the Loup and Elkhorn rivers that drain the Sand Hills region of Nebraska. Water diversions for mining and irrigation began in the 1840s in Colorado and Wyoming, and irrigation diversions in Nebraska began in the 1850s. Construction of dams for control of river flows commenced on the North Platte River in Wyoming in 1904. Additional dams and diversions in the North Platte, South Platte, and Platte rivers have extensively modified natural flow patterns and caused interruptions of flows. Pollution, from mining, industrial, municipal, and agricultural sources, and introductions of 24 nonnative species have also taken their toll. Fishes of the basin were little studied before changes in land use, pollution, and introduction of exotic species began. The current fish fauna totals approximately 100 species from 20 families. Native species richness declines westward, but some species find refugia in western headwaters streams. Declines in 26 native species has led to their being listing as species of concern by one or more basin states.

How direct and indirect non-native interactions can promote plant invasions, lead to invasional meltdown and inform management decisions.

2020 ◽  
pp. 153-176
Author(s):  
Sara E. Kuebbing
Keyword(s):  
Native Species ◽  
Native Plants ◽  
Full Range ◽  
Invasion Biology ◽  
Apparent Competition ◽  
Indirect Interactions ◽  
Competitive Interactions ◽  
Invasional Meltdown ◽  
Soil Microbial ◽  
Facilitative Interactions

Abstract In 1999, Daniel Simberloff and Betsy Von Holle introduced the term 'invasional meltdown'. The term and the concept have been embraced and critiqued but have taken a firm hold within the invasion biology canon. The original formulation of the concept argued two key points: first, biologists rarely study how non-natives interact with one another. Second, nearly all the conceptual models about the success and impact of invasive species are predicated on the importance of competitive interactions and an implicit assumption that non-natives should interfere with establishment, spread and impact of other non-natives. In response, Simberloff and Von Holle called for more research on invader interactions and proposed an alternative consequence of non-native species interactions - invasional meltdown - where facilitative interactions among non-natives could increase the invasion rate or ecological impacts in invaded systems. This chapter outlines the primary pathways in which direct and indirect interactions among non-natives could lead to invasional meltdown. It provides examples of how different types of interactions among non-natives could lead to net positive effects on the invasion success of non-native plants or the impact of non-native plants on invaded ecosystems. Direct effects are by far the most commonly explored form of non-native- non- native interaction, primarily focusing on plant mutualisms with pollinators, seed dispersers or soil microbial mutualists. There are, however, also examples of non-native plants that benefit from commensal and even herbivorous interactions with other non-natives. Indirect interactions among non-natives are very infrequently studied. Although examples are scarce, non-natives may indirectly benefit other non-native plants through trophic cascades, apparent competition and indirect mutualisms. It remains unclear whether indirect effects are important pathways to invasional meltdown. More work is needed on studying ecosystems that are invaded by multiple non-native species and we need to consider the full range of interactions among non-natives that could either stymie or promote their spread, population growth and impact. Only then can we address how common facilitative interactions are relative to competitive interactions among non-natives or provide robust suggestions on how to manage ecosystems.

Thinking through Scale: The Role of State Governance in Globalizing North Pacific Fisheries

10.1068/a3469 ◽  
2001 ◽  
Vol 33 (10) ◽  
pp. 1807-1827 ◽  
Author(s):  
Becky Mansfield
Keyword(s):  
United States ◽  
North Pacific ◽  
Global Economy ◽  
Urban Governance ◽  
Spatial Scales ◽  
Full Range ◽  
The United States ◽  
International Partnerships ◽  
The North ◽  
Static View

Debates about the relationship between globalization and state power have often relied on a static view of spatial scales as discrete stages for social interaction. Focusing instead on the ‘production of scale’, several researchers have argued that globalization leads to rescaling of the state, as regulatory powers are realigned both upwards to supranational regimes and downwards to regional, local, and urban governance structures. Although this perspective quite usefully treats scale as relational, this ‘glocalization’ argument remains somewhat schematic and does not allow for a full range of possible scalar configurations. Highlighting instead heterogeneity of scalar relations, in this paper I analyze the ways that United States' fishery development in the North Pacific produced both national power and transnational economic activity. After extending political jurisdiction over waters up to 200 nautical miles from shore, the United States implemented fishery development policies that emphasized the ‘Americanization’ of the Alaska pollock fishery at the expense of an international, particularly Japanese, fishery. The outcomes of these policies, however, have been international partnerships, foreign direct investment, and increased international trade, all of which have made the pollock industry simultaneously national and transnational. Efforts to assert and implement control over ocean territory produced both the national state and globalization, which were mutually reinforcing rather than antagonistic. Treating national states and the global economy as complex, contingent scalar configurations facilitates analysis of the causes of variability in state – economy relations.

Seawater warming at the northern reach for southern species: Gulf of Genoa, NW Mediterranean

2017 ◽  
Vol 98 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Carlo Nike Bianchi ◽  
Francesco Caroli ◽  
Paolo Guidetti ◽  
Carla Morri
Keyword(s):  
Mediterranean Sea ◽  
Native Species ◽  
Indigenous Species ◽  
Ligurian Sea ◽  
The North ◽  
Nw Mediterranean ◽  
The Mediterranean ◽  
Non Indigenous Species ◽  
Southern Species ◽  
North Western

Global warming is facilitating the poleward range expansion of plant and animal species. In the Mediterranean Sea, the concurrent temperature increase and abundance of (sub)tropical non-indigenous species (NIS) is leading to the so-called ‘tropicalization’ of the Mediterranean Sea, which is dramatically evident in the south-eastern sectors of the basin. At the same time, the colder north-western sectors of the basin have been said to undergo a process of ‘meridionalization’, that is the establishment of warm-water native species (WWN) previously restricted to the southern sectors. The Gulf of Genoa (Ligurian Sea) is the north-western reach for southern species of whatever origin in the Mediterranean. Recent (up to 2015) observations of NIS and WWN by diving have been collated to update previous similar inventories. In addition, the relative occurrences of both groups of southern species have been monitored by snorkelling between 2009 and 2015 in shallow rocky reefs at Genoa, and compared with the trend in air and sea surface temperatures. A total of 20 southern species (11 NIS and 9 WWN) was found. Two WWN (the zebra seabream Diplodus cervinus and the parrotfish Sparisoma cretense) and three NIS (the SW Atlantic sponge Paraleucilla magna, the Red Sea polychaete Branchiomma luctuosum, and the amphi-American and amphi-Atlantic crab Percnon gibbesi) are new records for the Ligurian Sea, whereas juveniles of the Indo-Pacific bluespotted cornetfish Fistularia commersonii have been found for the first time. While temperature has kept on increasing for the whole period, with 2014 and 2015 being the warmest years since at least 1950, the number of WWN increased linearly, that of NIS increased exponentially, contradicting the idea of meridionalization and supporting that of tropicalization even in the northern sectors of the Mediterranean basin.

Distribution and abundance of Rhynchocinetes typus (Crustacea: Decapoda), in different benthic community structures in northern Chile

2003 ◽  
Vol 83 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Luis M. Caillaux ◽  
Wolfgang B. Stotz
Keyword(s):  
Benthic Community ◽  
Subtidal Zone ◽  
Suspension Feeding ◽  
North Central ◽  
The North ◽  
Lessonia Trabeculata ◽  
Different Types ◽  
Community Types ◽  
Shrimp Abundance ◽  
Barren Grounds

An evaluation was carried out on the distribution and abundance of the rock shrimp Rhynchocinetes typus in the inshore subtidal zone on the north-central coast of Chile. A number of different benthic community types occur in the region which have different degrees of spatial complexity provided by the primary substratum and by the biotic communities colonizing the substratum. Shrimp abundance was estimated in five different community types including shallow and deep ‘barren grounds’, low encrusting communities, erect suspension feeding associations, and kelp beds of Lessonia trabeculata. The abundance of shrimp was determined on three different types of primary substratum (stones, boulders, rock mass) within each community. Rhynchocinetes typus occurred in all the communities studied, showing the highest abundance on the deep barren grounds and lowest abundance on the shallow barren grounds. The shrimp was found to prefer the stony areas, as these offered the greatest degree of refuge. The abundance of predators was not significantly different among the different communities. However, a decline of abundance of predators was apparent over the deep barren grounds.

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