Advances in methods for determining fecundity: application of the new methods to some marine fishes

Estimation of individual egg production (realized fecundity) is a key step either to understand the stock and recruit relationship or to carry out fisheries-independent assessment of spawning stock biomass using egg production methods. Many fish are highly fecund and their ovaries may weigh over a kilogram; therefore the work time can be consuming and require large quantities of toxic fixative. Recently it has been shown for Atlantic cod (Gadus morhua) that image analysis can automate fecundity determination using a power equation that links follicles per gram ovary to the mean vitellogenic follicular diameter (the autodiametric method). In this article we demonstrate the precision of the autodiametric method applied to a range of species with different spawning strategies during maturation and spawning. A new method using a solid displacement pipette to remove quantitative fecundity samples (25, 50, 100, and 200 milligram [mg]) is evaluated, as are the underlying assumptions to effectively fix and subsample the ovary. Finally, we demonstrate the interpretation of dispersed formaldehyde-fixed ovarian samples (whole mounts) to assess the presence of atretic and postovulatory follicles to replace labor intensive histology. These results can be used to estimate down regulation (production of atretic follicles) of fecundity during maturation

Monitoring Update of the Roughhead Grenadier Stock Assessment in NAFO Subareas 2 and 3

The revised catch history after 1987 is presented, total SA 2+3 roughhead grenadier catch in 2000 was 4767 tons. The trends in biomass estimates from four survey series are examined: Canadian fall, Canadian spring, Spanish spring 3NO and EU summer 3M. Only the Canadian fall surveys are considered to cover adequately the species distribution range. The biomass index from this survey in 2000 was 29139 t , 36 % of it in Div. 3L. Commercial catch include mainly ages between 5 and 10, with a peak at age 6. An age structured production model has been performed as a trial. The result of it indicate a moderate decrease in the total biomass but a sharp decrease in SSB. The F reference obtained is 0.41. The C/ B index using data from the Canadian fall survey is 0.16 (C/B1999 = 0.27)

Spanish Research Report for 1999

14 páginas, 18 tablasPeer reviewe

An Assessment for Roughhead Grenadier (Macrourus berglax) in NAFO Subareas 2 and 3.

It has been recognised that the recent catches of grenadiers by EU-Portugal and EU-Spain in Subarea 3, previously reported to NAFO as roundnose grenadiers, correspond to roughhead grenadier. Roughhead grenadier is taken as by-catch in the Greenland halibut fishery in the Regulatory Area mainly in Divisions 3LMN. Catches increased gradually and the largest proportion by country correspond to Spain and Portugal, with 6050 t. and 1089 t. respectively in 1998. A review of the biomass estimates from the available research surveys in Subareas 2 and 3 is presented. According to the Canadian fall surveys, it seems that the main part of the stock shifted from the northern Divisions (2GJand 3K) to the southern ones (3LN), and to greater depths (beyond 1000 m.) since early 90s. A review of the biological information available for this stock is also presented. Mean lengths (preanal fin lengths) of the catches show no decreasing trend since 1995. The age o fully recruitment to the fishery is 8, and the total mortality estimate (1997-1998) is Z = 0.43. Female age at maturity is 15, corresponding to a PFL of 26.5 cm. The Canadian fall survey series seems to be the best input for the assessment of this stock. At present the higher part of biomass is found in Div. 3L and 3N and at depths between 1000-1200 m. A yield per recruit has been performed using the input data presented in table 13. The partial recruitment vector comes from Cárdenas et al. (1995), The maturity curve at age from Murua and Motos (1997) and the mean weight at age from the 1998 agelength key. M is assumed as constant through the ages with a value of 0.2. The results of the yield per recruit analysis appears in Fig. 6. The estimated Fmax is 0.27 and F0.1 is 0.13. However it must be noted that this output is sensitive to possible changes in M, as if for instance M would be different between sexes, as suggest the results from Murua et al. (1999) and as it has been shown in the Greenland halibut (Anon. 1998). Any decreasing trend in the mean lengths, that would be an index of an excessive fishing pressure, is observed in the mean lengths of the catches since 1995 up to now. The available time series of catches at age is too short to analyse trends in the SSB, however it can be noted that only a 18 % and 10 % percent of the 1997 and 1998 catches respectively were above the female age at maturity (15 years). We have scarce information at the moment to assess an appropriate exploitation level, though survey series shows that at the current exploitation rate the biomass is increasing since 1994

Improving Emergency Plans through Public Engagement

Emergency plans are fundamental for the speedy and effective response in disaster situations. Plans are often constructed by teams of experts, who apply their knowledge to define response procedures, but lack part of location-specific knowledge that can be very relevant to make decisions during responses. Such knowledge is, however, in the minds of people who use those spaces every day, but are not involved in the planning processes. In this paper, we advocate for citizens' involvement in emergency plan elaboration via Public Participation, a mechanism long time used in other areas of e-government. We define a process for the elicitation of citizen's knowledge via public participation, and present the results of a study on its potential impact, where individuals used different collaborative tools to volunteer knowledge to be used in emergency plan improvement.Penadés Gramage, MC.; Vivacqua, AS.; Borges, M.; Canos Cerda, JH. (2011). Improving Emergency Plans through Public Engagement. http://hdl.handle.net/10251/1133

Spanish Research Report for 1998

11 páginas, 9 tablasPeer reviewe

Collaboration and Decision Making in Crisis Situations

[EN] Emergencies are critical situations that demand immediate action to avoid adverse consequences to life and property. Recent events around the world highlight the importance of the theme. A key challenge in Emergency Management is decision-making under time pressure, with an overload of unconfirmed, uncertain and conflicting information, including the management of many people, with distinct and possibly fluid roles, in different places. Collaboration in these settings is an interesting element, since emergency response generally involves multiple agencies and the public, which, having different views, protocols and priorities, must act in concert to handle the situation. In addition, an increasing amount of virtual information is necessary to inform and manage volunteers. The goal of this workshop is to identify and map the main challenges of collaboration in crisis situations, review current research methods and approaches to address them and address the lack of formal processes, structures, methodologies and tools.Adriana S Vivacqua is partially supported by CNPq grant 308425/2012-0 and FAPERJ grant E26/103.029/2012. Vaninha Vieira is partially supported by CNPq grant 490084/2013-3Vivacqua, AS.; Garcia, ACB.; Canos Cerda, JH.; Comes, M.; Vieira, V. (2016). Collaboration and Decision Making in Crisis Situations. ACM. 503-508. https://doi.org/10.1145/2818052.2855520S50350