18542 Federal Register / Vol. 62, No. 73 / Wednesday, April 16, 1997 / Rules and Regulations

subsample. The percentage of finfish in the

subsample will be used to estimate the total

finfish in the catch.

• Target species (weakfish and Spanish

mackerel) must be weighed as a species lot,

and each individual counted and length

measured. For large catches, a subsample of

selected individuals for each age-class shall

be measured.

• Information must be obtained on other

important species (collect total weight and

total numbers of individual species in

subsample to estimate total weight and total

numbers in catch). (Species list: Seatrouts

(weakfish, spotted, and silver), Spanish

mackerel, king mackerel, cobia, gag,

seabasses (black, bank, and rock), spot,

croaker, red drum, black drum, pompano,

kingfishes (southern and northern), flounders

(southern and summer), bluefish, scup,

juvenile sharks, sturgeon, shad, and sea

turtles (take only measurements that can be

taken without harming turtles).)

• A modified paired t-test is the statistical

technique to be used for analyzing the data.

• A minimum of 30 successful tows are

required to test a new or modified gear.

• A minimum catch (fish per tow) of five

weakfish and/or one Spanish mackerel is

required to qualify as a successful tow.

• Tow times, time of day, catch rates, and

fishing techniques should be comparable to

commercial operations.

• Consistent tow times are required in a

given series of tows that constitute a test for

an individual BRD. A nominal time window

(plus or minus 10 percent of tow time)

around a specific tow time is allowed.

• Basic operational cost differences should

be recorded.

• Shrimp retention must be recorded.

Statistical Procedures for Analyzing BRD

Evaluation Data

All experimental tows must be conducted

strictly under the guidelines specified under

the BRD testing protocol. To reduce problems

caused by no or low catches, a tow must

contain a minimum catch of five weakfish

and/or one Spanish mackerel in at least one

net for inclusion in the analysis. Once

conducted, the tow (and the corresponding

data) become the permanent part of the

record and cannot be discarded. Only the

successful tows (meeting the minimum catch

and other requirements) will count toward

the minimum required, however all tows will

be used in the analysis.

Statistical Approach

You should start with the assumption that

the BRD to be tested does not achieve the

minimum required reduction rate, say Ro.

This assumption will be accepted if the data

provide sufficient evidence to do so. Hence,

the hypotheses to be tested are as follows:

Ho: BRD does not achieve the minimum

required reduction rate,

R R i e R c c b

c

= o o b

− ≤ − − ≤ μ μ

μ

, . . ( ) . 1 0 μ μ

Ha : BRD does achieve the minimum

required reduction rate,

R R i e R c c b

c

= o o b

− > − − > μ μ

μ

, . . ( ) . 1 0 μ μ

Here R denotes the actual reduction rate

(unknown), Ro denotes the minimum

required reduction rate, μc denotes the actual

mean CPUE with the control, and μb denotes

the actual mean CPUE with the BRD.

With any hypothesis testing, there are two

risks involved, known as type I error

(rejecting the true Ho) and type II error

(accepting a false Ho). The probabilities of

committing these errors are denoted by alpha

and beta, respectively, and those are

inversely related to each other. As alpha

increases, beta decreases, and vice versa. The

above test will be conducted with an alpha

to be specified by the RA. The above

hypotheses should be tested using a

‘‘modified’’ paired t-test.

The CPUE values for the control and BRD

nets for each successful tow should be

computed first and these will be used in the

following computations. The test statistic to

be used is given by:

t Ro x y

s n d

= ( ) − −

/ , 1

0

Where:

x is the observed mean CPUE for the control,

y is the observed mean CPUE for the BRD,

sd0 is the standard deviation of di= (1—

Ro)xi—yi values,

n is the number of successful tows used in

the analysis, and i=

1,2, . . ., n.

The Ho will be rejected if t > -talpha, n-1,

where talpha, n-1 denotes the (1—alpha) 100th

percentile score in the t distribution with

(n—1) degrees of freedom.

The computation of beta (for various

assumed reduction rates, R1 < R0) is

somewhat involved and requires the

knowledge of unknown parameters (or at

least good estimates) of μc and alpha2

d0. Note

that alpha2

d0 is dependent on the Ro specified

(under H0) and equals:

(1—Ro)2 alpha2

xi + alpha2yi—2(1—Ro)p •

alphaxi • alphayi, where p is the population

correlation coefficient between xi and yi

values.

The computation of beta in advance (in the

absence of any preliminary data, i.e., without

good parameter estimates) is almost

impossible. More work in this direction is

still needed. However, it is clear that beta

could be reduced by increasing alpha or n or

both.

A (1—alpha) 100-percent two-sided

confidence interval on R consists of all

values of Ro for which

Ho: R = Ro (versus H∂R ≠Ro) cannot be

rejected at the level of significance of alpha.

One-sided confidence intervals on R could

also be computed appropriately.

[FR Doc. 97–9816 Filed 4–15–97; 8:45 am]

BILLING CODE 3510–22–P

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric

Administration

50 CFR Part 679

[Docket No. 961107312–7021–02; I.D.

041097E]

Fisheries of the Exclusive Economic

Zone Off Alaska; Species in the Rock

Sole/Flathead Sole/‘‘Other Flatfish’’

Fishery Category by Vessels Using

Trawl Gear in Bering Sea and Aleutian

Islands

AGENCY: National Marine Fisheries

Service (NMFS), National Oceanic and

Atmospheric Administration (NOAA),

Commerce.

ACTION: Closure.

SUMMARY: NMFS is closing directed

fishing for species in the rock sole/

flathead sole/‘‘other flatfish’’ fishery

category by

vessels using trawl gear in the Bering

Sea and Aleutian Islands management

area (BSAI). This action is necessary to

prevent exceeding the second seasonal

apportionment of the 1997 Pacific

halibut bycatch allowance specified for

the trawl rock sole/flathead sole/‘‘other

flatfish’’ fishery category.

EFFECTIVE DATE: 1200 hrs, Alaska local

time (A.l.t.), April 12, 1997, until 1200

hrs, A.l.t., July 1, 1997.

FOR FURTHER INFORMATION CONTACT:

Mary Furuness, 907–586-7228.

SUPPLEMENTARY INFORMATION: The

groundfish fishery in the BSAI exclusive

economic zone is managed by NMFS

according to the Fishery Management

Plan for the Groundfish Fishery of the

Bering Sea and Aleutian Islands Area

(FMP) prepared by the North Pacific

Fishery Management Council under
Federal Register / Vol. 62, No. 73 / Wednesday, April 16, 1997 / Rules and Regulations 18543

authority of the Magnuson-Stevens

Fishery Conservation and Management

Act. Fishing by U.S. vessels is governed

by regulations implementing the FMP at

subpart H of 50 CFR part 600 and 50

CFR part 679.

The second seasonal apportionment

of the 1997 halibut bycatch allowance

specified for the BSAI trawl rock sole/

flathead sole/‘‘other flatfish’’ fishery

category, which is defined at

§ 679.21(e)(3)(iv)(B)(2), was established

by the Final 1997 Harvest Specifications

of Groundfish for the BSAI (62 FR 7168,

February 18, 1997) as 130 mt.

In accordance with § 679.21(e)(7)(iv),

the Administrator, Alaska Region,

NMFS, has determined that the second

seasonal apportionment of the 1997

halibut bycatch allowance specified for

the trawl rock sole/flathead sole/‘‘other

flatfish’’ fishery in the BSAI has been

caught. Consequently, NMFS is closing

directed fishing for species in the rock

sole/flathead sole/‘‘other flatfish’’

fishery category by vessels using trawl

gear in the BSAI for the remainder of the

season.

Maximum retainable bycatch amounts

may be found in the regulations at

§ 679.20(e) and (f).

Classification

This action is required by 50 CFR

679.21 and is exempt from review under

E.O. 12866.

Authority: 16 U.S.C. 1801 et seq.

Dated: April 11, 1997.

Gary Matlock,

Director, Office of Sustainable Fisheries,

National Marine Fisheries Service.

[FR Doc. 97–9853 Filed 4–11–97; 4:34 pm]

BILLING CODE 3510–22–F