Non-native red alga Gracilaria vermiculophylla compensates for seagrass loss as blue crab nursery habitat in the emerging Chesapeake Bay ecosystem.

Non-native species can become deleterious or potentially beneficial as components of novel ecosystems. The non-native red macroalga Gracilaria vermiculophylla may provide nursery habitat where eelgrass Zostera marina has been extirpated in Chesapeake Bay. A mensurative experiment was conducted monthly May-October 2013 and 2014 in the York River, Chesapeake Bay, to evaluate hypotheses that Gracilaria (1) can compensate for the loss of seagrass nurseries by colonizing habitats where seagrass has been eliminated by environmental stress, and (2) is utilized by juvenile blue crabs (Callinectes sapidus) as nursery habitat. We quantified Gracilaria presence, percent cover, and biomass as a function of region (upriver, midriver, and downriver) and seagrass presence or absence using stratified random sampling, 20-m transects, and 0.0625-m2 quadrats. Gracilaria volume was measured and converted to dry weight. Effects of the factors and covariates temperature, salinity, dissolved oxygen, month, and year were analyzed using generalized linear models. Juvenile blue crab density was quantified in summer 2013 using suction sampling in Gracilaria and seagrass. A model with the collective effect of region and seagrass presence or absence (downriver seagrass, downriver unvegetated bottom, midriver unvegetated bottom) best predicted Gracilaria abundance. Gracilaria presence, percent cover, and biomass were highest in downriver seagrass, followed by downriver unvegetated bottom, and then midriver unvegetated bottom, where seagrass has been extirpated, supporting hypothesis (1). Gracilaria did not occur upriver, likely due to a lack of recruitment. Seagrass and Gracilaria housed similar densities of juvenile blue crabs, supporting hypothesis (2). We estimated that a single 40-ha cove system with Gracilaria could house 200,000 juvenile crabs as would a single 2.4-ha seagrass bed. Consequently, the numerous midriver and downriver cove systems in the York River could support millions of young juvenile blue crabs and thereby compensate for the loss of seagrass in the river and in other areas of Chesapeake Bay. At present, Gracilaria has no widespread negative impacts on seagrass in the York River or most regions of Chesapeake Bay, likely because percent cover and biomass are not excessively high at present. We posit that Gracilaria has become an important alternative nursery habitat for the blue crab in Chesapeake Bay and can potentially mitigate impacts of climate change on seagrass nursery habitats.

Friendship Security, But Not Friendship Intimacy, Moderates the Stability of Anxiety During Preadolescence.

A two-wave longitudinal study of 380 preadolescents (M age = 10.87) from largely middle-class schools in Montréal, Québec, Canada, assessed the hypothesis that friendship security, but not friendship intimacy, moderates the stability of anxiety during adolescence. This central but largely overlooked question about peer relations concerns which aspects of friendship account for the effects of friendship on emotional adjustment. Anxiety and friendship quality were measured via self-report questionnaires, employing the Network of Relationships Inventory for security and intimacy items. An index of friendship durability, which combined reciprocity and stability within first- and second-best friendship choices, was derived from sociometric measures. A latent variable path analysis examined with structural equation modeling showed that anxiety was less stable for children who perceived their friendships as secure. The moderating effect of intimacy was statistically nonsignificant. A follow-up analysis showed that the effects of security did not result from friendship durability. These findings provide support for the long-standing but previously unaddressed hypothesis that security, rather than intimacy, accounts for friendship's effect on anxiety reduction during early adolescence.

Psychiatrists' Perceptions of World of Warcraft and Other MMORPGs.

Video game use, particularly massively-multiplayer online games (MMOs) and massively-multiplayer online role-playing games (MMORPGs), has been a focus of considerable research in recent years. However, little is known regarding how mental health workers perceive patients and clients who report playing them. The present study examines whether psychiatrists play MMOs/MMORPGs and how they perceive those who play them. Psychiatrists (N = 48) at a tertiary care centre in Canada completed a questionnaire assessing history of playing video games as well as whether they associate such use with psychopathology. Only 36.7 % believed there was an association between psychopathology and MMO/MMORPG use. Implications for clinical practice and future research are discussed.

Psychiatrists' Perceptions of Facebook and Other Social Media.

The literature has seen a surge in research on the mental health impacts of technologies such as Facebook, Twitter and other social media, but little is known regarding how mental health workers perceive patients and clients who report use of such technologies. The present study examines how psychiatrists perceive social media and whether they make use of it. Psychiatrists (N = 48) at a tertiary care centre in Canada completed a questionnaire assessing history of using social networking sites (SNSs) such as Facebook and Google Plus and status update sites (SUSs) such as Twitter and Livejournal and whether they associate them with psychopathology. 38.5 % have used SNSs and 9.8 % have used SUSs. Only 37 % believed there was an association between psychopathology and SNSs while 33 % believed there was an association between psychopathology and SUSs. Implications for clinical practice and future research are discussed.