Development of new nuclear markers and characterization of single nucleotide polymorphisms in kelp gull (Larus dominicanus)

The present study seeks to develop nuclear markers for the kelp gull (Larus dominicanus). We hereby report the characterization of 12 independent nuclear introns, where 104 single nucleotide polymorphisms (SNPs) in 8138 sequenced base pairs were observed. These SNP markers are the first to be designed for genotyping a gull species. The markers will provide useful tools for understanding which processes act or acted upon kelp gulls to cause their low genetic variability in mitochondrial DNA. In addition, these markers open a new opportunity for population genetic and evolutionary studies in the Laridae group.

The diet of Pacific gulls (Larus pacificus) breeding at Seal Island in northern Bass Strait

The endemic Pacific gull (Larus pacificus) is Australia's largest larid, and though little is currently known of its foraging ecology, its size and wide distribution suggest that it may play an important role within the marine environment. In the present study, regurgitate pellets collected from Seal Island in northern Bass Strait were used to compare intra- and interannual trends in diet composition. The main taxa identified in pellets were the common diving-petrel (Pelecanoides urinatrix), leatherjacket species (Family Monacanthidae), short-tailed shearwater (Puffinus tenuirostris) and mirror bush (Coprosma repens). Analysis of similarity (ANOSIM) identified no significant differences in numerical abundance of the dominant prey species between years, suggesting that the prey base in this region is temporally consistent or that the gulls consume low enough numbers to be unaffected by fluctuation in prey populations. Diving-petrels were consumed in consistently high numbers, suggesting the gulls may be an important predator of this species, or that the gulls are particularly skilled at foraging for them. © CSIRO 2014.

Heterospecific sociality of birds on beaches from southeastern Brazil

Studies on the sociality of heterospecific assemblages of birds have promoted a greater understanding of the types of interactions and survivorship between coexisting species. This study verified the group compositions in bird assemblages and analyzed the sociality of migratory and resident species on sandy beaches of southeastern Brazil. A transect was established on the median portion of beaches and all the groups of bird species (monospecific, heterospecific) and solitary individuals were registered four days per month from November 2006 to April 2007. The sociality of each species was calculated by its frequency in heterospecific groups, its proportional number of contacts with other species in heterospecific groups, and the number of species that it associated with. Semipalmated Sandpiper Calidris pusilla (Linnaeus, 1766) and Semipalmated Plover Charadrius semipalmatus Bonaparte, 1825 (both migratory) had the highest degree of sociality and did not show a preference to associate with either residents or migratory species. Sanderling Calidris alba (Pallas, 1764) (migratory) occupied the third position in the sociality rank and associated with migratory species frequently. Southern Caracara Carara plancus (Miller, 1777) and Black Vulture Coragyps atratus (Beschstein, 1793) (both resident) were uniquely found among heterospecific groups with necrophagous and resident species. Kelp Gull Larus dominicanus Lichtenstein, 1823 (resident) associated more frequently with resident species. The sociality in assemblages of birds may promote advantages such as an increased collective awareness in dangerous situations and indication of sites with abundant food sources.

Genetic variability in mitochondrial and nuclear genes of Larus dominicanus (Charadriiformes, Laridae) from the Brazilian coast

Several phylogeographic studies of seabirds have documented low genetic diversity that has been attributed to bottleneck events or individual capacity for dispersal. Few studies have been done in seabirds on the Brazilian coast and all have shown low genetic differentiation on a wide geographic scale. The Kelp Gull is a common species with a wide distribution in the Southern Hemisphere. In this study, we used mitochondrial and nuclear markers to examine the genetic variability of Kelp Gull populations on the Brazilian coast and compared this variability with that of sub-Antarctic island populations of this species. Kelp Gulls showed extremely low genetic variability for nnitochondrial markers (cytb and ATPase) and high diversity for a nuclear locus (intron 7 of the beta-fibrinogen). The intraspecific evolutionary history of Kelp Gulls showed that the variability found in intron 7 of the beta-fibrinogen gene was compatible with the variability expected under neutral evolution but suggested an increase in population size during the last 10,000 years. However, none of the markers revealed evidence of a bottleneck population. These findings indicate that the recent origin of Kelp Gulls is the main explanation for their nuclear diversity, although selective pressure on the mtDNA of this species cannot be discarded.

Kelp detection in highly dynamic environments using texture recognition

This paper describes a texture recognition based method for segmenting kelp from images collected in highly dynamic shallow water environments by an Autonomous Underwater Vehicle (AUV). A particular challenge is image quality that is affected by uncontrolled lighting, reduced visibility, significantly varying perspective due to platform egomotion, and kelp sway from wave action. The kelp segmentation approach uses the Mahalanobis distance as a way to classify Haralick texture features from sub-regions within an image. The results illustrate the applicability of the method to classify kelp allowing construction of probability maps of kelp masses across a sequence of images.

Report of Pendleton artificial reef studies with recommendations for constructing a kelp reef

(Document pdf contains 64 pages)

Development of kelp rockfish, Sebastes atrovirens (Jordan and Gilbert 1880), and brown rockfish, S. auriculatus (Girard 1854), from birth to pelagic juvenile stage, with notes on early larval development of black-and-yellow rockfish, S. chrysomelas (Jordan and Gilbert 1880), reared in the laboratory (Pisces: Sebastidae).

Larval kelp (Sebastes atrovirens), brown (S. auriculatus), and blackand-yellow (S. chrysomelas) rockfish were reared from known adults, to preflexion stage, nine days after birth for S. chrysomelas, to late postflexion stage for S. atrovirens, and to pelagic juvenile stage for S. auriculatus. Larval S. atrovirens and S. chrysomelas were about 4.6 mm body length (BL) and S. auriculatus about 5.2 mm BL at birth. Both S. atrovirens and S. auriculatus underwent notochord flexion at about 6–9 mm BL. Sebastes atrovirens transform to the pelagic juvenile stage at about 14–16 mm BL and S. auriculatus transformed at ca. 25 mm BL. Early larvae of all three species were characterized by melanistic pigment dorsally on the head, on the gut, on most of the ventral margin of the tail, and in a long series on the dorsal margin of the tail. Larval S. atrovirens and S. auriculatus developed a posterior bar on the tail during the flexion or postflexion stage. In S. atrovirens xanthic pigment resembled the melanistic pattern throughout larval development. Larval S. auriculatus lacked xanthophores except on the head until late preflexion stage, when a pattern much like the melanophore pattern gradually developed. Larval S. chrysomelas had extensive xanthic pigmentation dorsally, but none ventrally, in preflexion stage. All members of the Sebastes subgenus Pteropodus (S. atrovirens, S. auriculatus, S. carnatus, S. caurinus, S. chrysomelas, S. dalli, S. maliger, S. nebulosus, S. rastrelliger) are morphologically similar and all share the basic melanistic pigment pattern described here. Although the three species reared in this study can be distinguished on the basis of xanthic pigmentation, it seems unlikely that it will be possible to reliably identify field-collected larvae to species using traditional morphological and melanistic pigmentation characters. (PDF file contains 36 pages.)

The Invertebrate Assemblage Associated with Macrocystis pyrifera and its Utilization as a Food Resource by Kelp Forest Fishes

The present study was designed to examine the following: (1) the taxonomic. spatial, and temporal patterns of availability of all invertebrate species associated with Macrocystis (excluding protozoans and nematodes); (2) the utilization of this invertebrate assemblage as food by kelp forest fishes within the Macrocystis "foliage- searching" feeding guild, as well as proximal mechanisms leading to observed patterns of resource partitioning; and (3) the dynamic relationship between availability and utilization of this food resource. The approach was largely descriptive. with observations collected during a 19-month period from June 1975 to December 1976. Chapter I is an investigation of the resource utilization patterns of four species of kelp forest fishes with respect to food-related resource dimensions. and tests aspects of current theory involving inter- and intraspecific competition. Chapter II is a detailed examination of the invertebrate assemblage associated with Macrocystis and presents life histories of the fishes examined during this study. (PDFs contains 387 pages, chapter 1 is 203 pages, chapter 2 is 184 pages)

Implications of substrate complexity and kelp variability for south-central Alaskan nearshore fish communities

Understanding the interactions between kelp beds and nearshore fish is essential because anthropogenic changes and natural variability in these beds may affect available habitat for fishes. In this study fish communities were investigated in south-central Alaska kelp beds characterized by a range of substrate complexity and varying densities of both perennial understory kelps and annual canopy kelps. Many of the observed fish species, as well as understory and canopy kelps, were positively associated with structurally complex substratum. Targeted canopy and understory kelp beds supported seasonal populations of adult and juvenile Pacific cod (Gadus macrocephalus), rockfishes (Sebastes spp.), and year-round populations of greenlings (Hexagrammos spp.). Monthly changes in kelp and fish communities ref lected seasonal changes; the densities of some species were greatest during periods with higher temperatures. This work illustrates the importance of structurally complex kelp beds with persistent understory kelp populations as important fish habitat for several commercially and recreationally important fishes.

The food habits of four kelp-bed rockfishes (Scorpaenidae, Sebastes) off Santa Barbara, California

The diets of four common rockfishes from the kelp beds near Santa Barbara, California, were determined by gut contents analysis, and related to feeding strategies. The guts of one hundred specimens of each species were examined, and the importance of prey evaluated by their frequency of occurrence, numbers, and volumes. The volumes of stomach contents were standardized for the size of specimen. Estimates of overlap in diet between the species were made. Sebastes atrovirens fed primarily on small animals from the kelp canopy, and may have employed a browsing rather than pursuing strategy of feeding. It showed low overlap in diet with the three bottom-dwelling species, S. carnatus, S. chrysomelas, and S. vexillaris, all of which preferred larger types of prey and seemed more like pursuers. The closely related S. carnatus and S. chrysomelas were quite similar in diet, eating primarily medium sized demersal invertebrates, especially crabs and shrimp. S. vexillaris ate fewer crabs and shrimp but more large-sized fish and octopus than the latter two species. Its more active life style indicates that it may react to prey at greater distances and have a larger home range than these species, as has been predicted for pursuers feeding on larger (and rarer) prey.

Suspension culture of gametophytes of transgenic kelp in a photobioreactor

Transgenic Laminaria japonica gametophytes producing a recombinant tissue-type plasminogen activator (rtPA) protein, which is an effective third-generation thrombolytic agent for acute myocardial infarction (AMI), were cultured in an illuminated bubble column bioreactor. A maximum final dry cell weight of 1120 mg l(-1) was obtained in batch culture with an initial dry cell weight of 126 mg l(-1) and with aeration rate of 1.2 l air min(-1) l(-1) culture, nitrate at 1.5 mM and phosphate at 0.17 mM. The yield of rtPA was 56 mu g g(-1) dry cell wt. This is the first report regarding cultivation of a transgenic macroalga in a bioreactor.

Transforming kelp into a marine bioreactor

The past decade has seen the genetic engineering of various types of seaweed. To date, genetic transformation studies have been carried out in several seaweeds, including the red seaweeds Porphyra, Gracilaria, Grateloupia, Kappaphyclus and Ceramium and the green seaweed Ulva. A genetic transformation model system has been established in the most commonly cultivated seaweed, the brown seaweed Laminaria japonica (kelp), based on the transfer of technology used in land plant transformation and also by modulating the seaweed life cycle. This model showed the potential for application of transgenic kelp to the production of valuable products and an indoor cultivation system for transgenic kelp was proposed, taking into account necessary factors for bio-safety. In this review, the establishment at use of the kelp transformation model is introduced, highlighting the potential for transforming kelp into a marine bioreactor.